diff --git a/README.md b/README.md
index c262ce69..23eaa371 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,175 @@
 
 jsPsych is a JavaScript library for creating behavioral experiments that run in a web browser. jsPsych creates a framework for defining experiments and provides a set of flexible plugins that create different kinds of tasks a subject could complete during an experiment. By assembling different plugins together and customizing the parameters of each, it is possible to create many different types of experiments.
 
+
+Code Demos
+----------
+
+Demo 1 with the instructions plugin:
+<div display="flex">
+<img src="https://user-images.githubusercontent.com/14092539/28126774-801ea42e-66f8-11e7-9b6a-c8bad0026bec.gif" align="right" width=50% />
+
+<div markdown="1" style="width: 50%;">
+<sub>
+
+```javascript
+
+
+
+
+
+
+
+
+
+
+
+
+
+    var trial = {       
+        type: 'instructions',     
+        pages: [      
+        'Welcome to the experiment. Click next to begin.',      
+        '<div>In this experiment, you will view a ' +       
+        'series of images and answer questions.<br>' +      
+        'Answer with the keys "y" or "n".',     
+        'Here is an example:<br><br> ' +        
+        '<img src="img/age/of2.jpg"></img><br><br>' +       
+        'Is this person OLD or YOUNG?'      
+        ],        
+        show_clickable_nav: true      
+    }       
+
+    jsPsych.init({      
+        timeline: [trial],        
+    });
+    
+    
+    
+    
+    
+    
+    
+    
+    
+    
+    
+```
+
+</sub>
+</div>
+</div>
+
+
+Demo 2 with the image-keyboard-response plugin:
+<div display="flex">
+<img src="https://user-images.githubusercontent.com/14092539/28125911-0504cca2-66f6-11e7-8f5b-c9686f63aaa8.gif" align="right" width=50% />
+
+<div markdown"2" style="width: 50%;">
+<sub>
+
+```javascript
+
+
+
+
+
+
+
+  var trial_1 = {
+	type: "image-keyboard-response",
+    stimulus: 'img/happy_face_1.jpg',
+	choices: [89, 78],
+	prompt: '<p>Is this face happy? Y or N.</p>'
+  }
+
+  var trial_2 = {
+    type: 'image-keyboard-response',
+    stimulus: 'img/sad_face_2.jpg',
+    choices: [89, 78], // Y or N
+    prompt: '<p>Is this face happy? Y or N.</p>'
+  }
+
+  var trial_3 = {
+    type: 'image-keyboard-response',
+    stimulus: 'img/happy_face_2.jpg',
+    choices: [89, 78], // Y or N
+    prompt: '<p>Is this face happy? Y or N.</p>',
+  }
+
+
+  jsPsych.init({
+    timeline: [trial_1, trial_2, trial_3],
+    default_iti: 250
+  });
+  
+  
+  
+  
+  
+  
+  
+```
+</sub>
+</div>
+</div>
+
+
+And for a slightly longer experiment example, demo 3 with the html-keyboard-response plugin. Also shows data after experiment ends:
+<div display="flex">
+<img src="https://user-images.githubusercontent.com/14092539/28126802-97b50d08-66f8-11e7-9a45-46561ab51a5f.gif" align="right" width=50% />
+
+<div markdown="3" style="width: 50%;">
+<sub>
+
+```javascript
+var test_stimuli = [
+  { stimulus: "<<<<<", data: { stim_type: 'congruent'} },
+  { stimulus: ">>>>>", data: { stim_type: 'congruent'} },
+  { stimulus: "<<><<", data: { stim_type: 'incongruent'} },
+  { stimulus: ">><>>", data: { stim_type: 'incongruent'} } ];
+  
+var test = {
+  timeline: [{
+     type: 'html-keyboard-response',
+     choices: [37, 39],
+     stimulus: jsPsych.timelineVariable('stimulus'),
+     data: jsPsych.timelineVariable('data'),
+     post_trial_gap: 1500,
+     response_ends_trial: true }],
+  timeline_variables: test_stimuli,
+  sample: {type: 'fixed-repetitions', size: 2}
+};
+  
+var debrief = {
+  type: "html-keyboard-response",
+  stimulus: function() {
+  var congruent_rt = Math.round(jsPsych.data.get()
+      .filter({stim_type: 'congruent'}).select('rt').mean());
+  var incongruent_rt = Math.round(jsPsych.data.get()
+      .filter({stim_type: 'incongruent'}).select('rt').mean());
+  return "<p>Your average response time for congruent trials"+ 
+  "was <strong>"+congruent_rt+"ms</strong>.</p>"+
+  "<p>Your average response time for incongruent trials was"+
+  "<strong>"incongruent_rt + "ms</strong>.</p>";
+  }
+};
+
+var timeline = [];
+timeline.push(test);
+timeline.push(debrief);
+jsPsych.init({
+   timeline: timeline,
+   on_finish: function() {
+       jsPsych.data.displayData();
+   }
+});
+```
+
+</sub>
+</div>
+</div>
+
 Documentation
 -------------
 
diff --git a/examples/demos/demo_1.html b/examples/demos/demo_1.html
new file mode 100644
index 00000000..504feeb6
--- /dev/null
+++ b/examples/demos/demo_1.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <script src="../jspsych.js"></script>
+        <script src="../plugins/jspsych-instructions.js"></script>
+        <link rel="stylesheet" href="../css/jspsych.css">
+    </head>
+    <body>
+    </body>
+    <script>
+    var trial = {       
+        type: 'instructions',     
+        pages: [      
+        'Welcome to the experiment. Click next to begin.',      
+        '<div>In this experiment, you will view a ' +       
+        'series of images and answer questions.<br>' +      
+        'Answer with the keys "y" or "n".',     
+        'Here is an example:<br><br> ' +        
+        '<img src="img/age/of2.jpg"></img><br><br>' +       
+        'Is this person OLD or YOUNG?'      
+        ],        
+        show_clickable_nav: true      
+    }       
+
+    jsPsych.init({      
+        timeline: [trial],        
+    });
+    </script>
+</html>
\ No newline at end of file
diff --git a/examples/demos/demo_2.html b/examples/demos/demo_2.html
new file mode 100644
index 00000000..0613ee3e
--- /dev/null
+++ b/examples/demos/demo_2.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<script src="../jspsych.js"></script>
+	<script src="../plugins/jspsych-image-keyboard-response.js"></script>
+	<link rel="stylesheet" href="../css/jspsych.css"></link>
+	<style>
+		img {
+			width: 300px;
+		}
+	</style>
+</head>
+<body>
+</body>
+<script>
+	var trial_1 = {
+		type: "image-keyboard-response",
+		stimulus: 'img/happy_face_1.jpg',
+		choices: [89, 78],
+		prompt: '<p class="center-content">Is this face happy? Y or N.</p>'
+  }
+
+  var trial_2 = {
+    type: 'image-keyboard-response',
+    stimulus: 'img/sad_face_2.jpg',
+    choices: [89, 78], // Y or N
+    prompt: '<p class="center-content">Is this face happy? Y or N.</p>'
+  }
+
+  var trial_3 = {
+    type: 'image-keyboard-response',
+    stimulus: 'img/happy_face_2.jpg',
+    choices: [89, 78], // Y or N
+    prompt: '<p class="center-content">Is this face happy? Y or N.</p>',
+  }
+
+
+  jsPsych.init({
+    timeline: [trial_1, trial_2, trial_3],
+    default_iti: 250
+  });
+</script>
+</html>
\ No newline at end of file
diff --git a/examples/demos/demo_3.html b/examples/demos/demo_3.html
new file mode 100644
index 00000000..b0b84301
--- /dev/null
+++ b/examples/demos/demo_3.html
@@ -0,0 +1,58 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <script src="../jspsych.js"></script>
+        <script src="../plugins/jspsych-html-keyboard-response.js"></script>
+        <link rel="stylesheet" href="../css/jspsych.css">
+        <style>
+        #jspsych-html-keyboard-response-stimulus {
+            font-size: 500%;
+        }
+        </style>
+    </head>
+    <body>
+    </body>
+    <script>
+        var test_stimuli = [
+          { stimulus: "<<<<<", data: { stim_type: 'congruent'} },
+          { stimulus: ">>>>>", data: { stim_type: 'congruent'} },
+          { stimulus: "<<><<", data: { stim_type: 'incongruent'} },
+          { stimulus: ">><>>", data: { stim_type: 'incongruent'} }
+        ];
+
+        var test = {
+          timeline: [{
+            type: 'html-keyboard-response',
+            choices: [37, 39],
+            stimulus: jsPsych.timelineVariable('stimulus'),
+            data: jsPsych.timelineVariable('data'),
+            post_trial_gap: 1500,
+            response_ends_trial: true
+          }],
+          timeline_variables: test_stimuli,
+          sample: {type: 'fixed-repetitions', size: 2}
+        };
+
+        var debrief = {
+          type: "html-keyboard-response",
+          stimulus: function() {
+            var congruent_rt = Math.round(jsPsych.data.get()
+              .filter({stim_type: 'congruent'}).select('rt').mean());
+            var incongruent_rt = Math.round(jsPsych.data.get().filter({stim_type: 'incongruent'}).select('rt').mean());
+            return "<p style='font-size:25px'>Your average response time for congruent trials was <strong>" + congruent_rt + "ms</strong>.</p>"+
+            "<p style='font-size:25px'>Your average response time for incongruent trials was <strong>" + incongruent_rt + "ms</strong>.</p>";
+          }
+        };
+
+        var timeline = [];
+        timeline.push(test);
+        timeline.push(debrief);
+
+        jsPsych.init({
+            timeline: timeline,
+            on_finish: function() {
+                jsPsych.data.displayData();
+            }
+        });
+    </script>
+</html>
\ No newline at end of file
diff --git a/plugins/jspsych-animation.js b/plugins/jspsych-animation.js
index 0a916cb2..ef81f074 100644
--- a/plugins/jspsych-animation.js
+++ b/plugins/jspsych-animation.js
@@ -58,12 +58,6 @@ jsPsych.plugins.animation = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    trial.frame_time = trial.frame_time || 250;
-    trial.frame_isi = trial.frame_isi || 0;
-    trial.sequence_reps = trial.sequence_reps || 1;
-    trial.choices = trial.choices || jsPsych.ALL_KEYS;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-
     var interval_time = trial.frame_time + trial.frame_isi;
     var animate_frame = -1;
     var reps = 0;
diff --git a/plugins/jspsych-audio-button-response.js b/plugins/jspsych-audio-button-response.js
index 40e0411b..f51eaad4 100644
--- a/plugins/jspsych-audio-button-response.js
+++ b/plugins/jspsych-audio-button-response.js
@@ -30,39 +30,51 @@ jsPsych.plugins["audio-button-response"] = (function() {
 				no_function: false,
 				description: ''
 			},
-      		button_html: {
-        		type: jsPsych.plugins.parameterType.HTML_STRING,
-        		default: '<button class="jspsych-btn">%choice%</button>',
-        		no_function: false,
-        		array: true,
-        		description: ''
-      		},
-     	    prompt: {
-        		type: jsPsych.plugins.parameterType.STRING,
-        		default: '',
-        		no_function: false,
-        		description: ''
-      		},
-      		trial_duration: {
-        		type: jsPsych.plugins.parameterType.INT,
-        		default: -1,
-        		no_function: false,
-        		description: ''
-      		},
-      		response_ends_trial: {
-        		type: jsPsych.plugins.parameterType.BOOL,
-        		default: true,
-        		no_function: false,
-        		description: ''
-      		},
-      		trial_ends_after_audio: {
-        		type: jsPsych.plugins.parameterType.BOOL,
-       			default: false,
-        		no_function: false,
-        		description: ''
-      	},
-    	}
-  	}
+      button_html: {
+        type: jsPsych.plugins.parameterType.HTML_STRING,
+        default: '<button class="jspsych-btn">%choice%</button>',
+        no_function: false,
+        array: true,
+        description: ''
+      },
+      prompt: {
+        type: jsPsych.plugins.parameterType.STRING,
+        default: '',
+        no_function: false,
+        description: ''
+      },
+      trial_duration: {
+        type: jsPsych.plugins.parameterType.INT,
+        default: -1,
+        no_function: false,
+        description: ''
+      },
+      margin_vertical: {
+        type: jsPsych.parameterType.STRING,
+        default: '0px',
+        no_function: false,
+        description: ''
+      },
+      margin_horizontal: {
+        type: jsPsych.parameterType.STRING,
+        default: '8px',
+        no_function: false,
+        description: ''
+      },
+      response_ends_trial: {
+        type: jsPsych.plugins.parameterType.BOOL,
+        default: true,
+        no_function: false,
+        description: ''
+      },
+      trial_ends_after_audio: {
+        type: jsPsych.plugins.parameterType.BOOL,
+        default: false,
+        no_function: false,
+        description: ''
+      },
+    }
+  }
 
   	plugin.trial = function(display_element, trial) {
 
diff --git a/plugins/jspsych-audio-keyboard-response.js b/plugins/jspsych-audio-keyboard-response.js
index cc5f2c64..e44f53df 100644
--- a/plugins/jspsych-audio-keyboard-response.js
+++ b/plugins/jspsych-audio-keyboard-response.js
@@ -60,13 +60,6 @@ jsPsych.plugins["audio-keyboard-response"] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameters
-    trial.choices = trial.choices || jsPsych.ALL_KEYS;
-    trial.response_ends_trial = (typeof trial.response_ends_trial === 'undefined') ? true : trial.response_ends_trial;
-    trial.trial_ends_after_audio = (typeof trial.trial_ends_after_audio === 'undefined') ? false : trial.trial_ends_after_audio;
-    trial.trial_duration = trial.trial_duration || -1; // if -1, then wait for response forever
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-
     // setup stimulus
     var context = jsPsych.pluginAPI.audioContext();
     if(context !== null){
diff --git a/plugins/jspsych-audio-slider-response.js b/plugins/jspsych-audio-slider-response.js
index 33a0e266..2fe91f54 100644
--- a/plugins/jspsych-audio-slider-response.js
+++ b/plugins/jspsych-audio-slider-response.js
@@ -19,6 +19,30 @@ jsPsych.plugins['audio-slider-response'] = (function() {
         no_function: false,
         description: ''
       },
+      min: {
+        type: jsPsych.plugins.parameterType.INT,
+        default: 0,
+        no_function: false,
+        description: ''
+      },
+      max: {
+        type: jsPsych.plugins.parameterType.INT,
+        default: 100,
+        no_function: false,
+        description: ''
+      },
+      step: {
+        type: jsPsych.plugins.parameterType.INT,
+        default: 1,
+        no_function: false,
+        description: ''
+      },
+      button_label: {
+        type: jsPsych.plugins.parameterType.STRING,
+        default: 'Next',
+        no_function: false,
+        description: ''
+      },
       trial_duration: {
         type: jsPsych.plugins.parameterType.INT,
         default: -1,
@@ -37,21 +61,17 @@ jsPsych.plugins['audio-slider-response'] = (function() {
         no_function: false,
         description: ''
       },
+      prompt: {
+        type: jsPsych.plugins.parameterType.STRING,
+        default: '',
+        no_function: false,
+        description: ''
+      }
     }
   }
 
     plugin.trial = function(display_element, trial) {
 
-    trial.min = trial.min || 0;
-    trial.max = trial.max || 100;
-    trial.step = trial.step || 1;
-    trial.button_label = typeof trial.button_label === 'undefined' ? 'Next' : trial.button_label;
-    trial.response_ends_trial = (typeof trial.response_ends_trial == 'undefined') ? true : trial.response_ends_trial;
-    trial.trial_ends_after_audio = (typeof trial.trial_ends_after_audio === 'undefined') ? false : trial.trial_ends_after_audio;
-    trial.stimulus_duration = trial.stimulus_duration || -1;
-    trial.trial_duration = trial.trial_duration || -1;
-    trial.prompt = trial.prompt || "";
-
     // setup stimulus
     var context = jsPsych.pluginAPI.audioContext();
     if(context !== null){
diff --git a/plugins/jspsych-call-function.js b/plugins/jspsych-call-function.js
index 214976dc..ae329dae 100644
--- a/plugins/jspsych-call-function.js
+++ b/plugins/jspsych-call-function.js
@@ -20,17 +20,12 @@ jsPsych.plugins['call-function'] = (function() {
         default: undefined,
         no_function: false,
         description: ''
-      }
+      },
     }
   }
 
   plugin.trial = function(display_element, trial) {
-
-    // a rare case where we override the default experiment level
-    // value of this parameter, since this plugin should be invisible
-    // to the subject of the experiment
-    trial.post_trial_gap = typeof trial.post_trial_gap == 'undefined' ? 0 : trial.post_trial_gap
-
+    trial.post_trial_gap = 0;
     var return_val = trial.func();
 
     var trial_data = {
diff --git a/plugins/jspsych-categorize-animation.js b/plugins/jspsych-categorize-animation.js
index ea9a4e43..670bf47d 100644
--- a/plugins/jspsych-categorize-animation.js
+++ b/plugins/jspsych-categorize-animation.js
@@ -55,7 +55,7 @@ jsPsych.plugins["categorize-animation"] = (function() {
       },
       frame_time: {
         type: jsPsych.plugins.parameterType.INT,
-        default: 250,
+        default: 500,
         no_function: false,
         description: ''
       },
@@ -88,18 +88,6 @@ jsPsych.plugins["categorize-animation"] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // set default values
-    trial.choices = trial.choices || jsPsych.ALL_KEYS;
-    trial.sequence_reps = trial.sequence_reps || 1;
-    trial.key_answer = trial.key_answer;
-    trial.text_answer = (typeof trial.text_answer === 'undefined') ? "" : trial.text_answer;
-    trial.correct_text = trial.correct_text || "Correct.";
-    trial.incorrect_text = trial.incorrect_text || "Wrong.";
-    trial.allow_response_before_complete = trial.allow_response_before_complete || false;
-    trial.frame_time = trial.frame_time || 500;
-    trial.feedback_duration = trial.feedback_duration || 2000;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? '' : trial.prompt;
-
     var animate_frame = -1;
     var reps = 0;
 
diff --git a/plugins/jspsych-categorize-html.js b/plugins/jspsych-categorize-html.js
index 6643fb00..6557d545 100644
--- a/plugins/jspsych-categorize-html.js
+++ b/plugins/jspsych-categorize-html.js
@@ -41,13 +41,13 @@ jsPsych.plugins['categorize-html'] = (function() {
       },
       correct_text: {
         type: jsPsych.plugins.parameterType.STRING,
-        default: 'Correct.',
+        default: "<p class='feedback'>Correct</p>",
         no_function: false,
         description: ''
       },
       incorrect_text: {
         type: jsPsych.plugins.parameterType.STRING,
-        default: 'Wrong.',
+        default: "<p class='feedback'>Incorrect</p>",
         no_function: false,
         description: ''
       },
@@ -77,7 +77,7 @@ jsPsych.plugins['categorize-html'] = (function() {
       },
       timeout_message: {
         type: jsPsych.plugins.parameterType.STRING,
-        default: 'Please respond faster.',
+        default: "<p>Please respond faster.</p>",
         no_function: false,
         description: ''
       },
@@ -104,21 +104,6 @@ jsPsych.plugins['categorize-html'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameters
-    trial.choices = trial.choices || jsPsych.ALL_KEYS;
-    trial.text_answer = (typeof trial.text_answer === 'undefined') ? "" : trial.text_answer;
-    trial.correct_text = (typeof trial.correct_text === 'undefined') ? "<p class='feedback'>Correct</p>" : trial.correct_text;
-    trial.incorrect_text = (typeof trial.incorrect_text === 'undefined') ? "<p class='feedback'>Incorrect</p>" : trial.incorrect_text;
-    trial.show_stim_with_feedback = (typeof trial.show_stim_with_feedback === 'undefined') ? true : trial.show_stim_with_feedback;
-    trial.force_correct_button_press = (typeof trial.force_correct_button_press === 'undefined') ? false : trial.force_correct_button_press;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? '' : trial.prompt;
-    trial.show_feedback_on_timeout = (typeof trial.show_feedback_on_timeout === 'undefined') ? false : trial.show_feedback_on_timeout;
-    trial.timeout_message = trial.timeout_message || "<p>Please respond faster.</p>";
-    // timing params
-    trial.stimulus_duration = trial.stimulus_duration || -1; // default is to show image until response
-    trial.trial_duration = trial.trial_duration || -1; // default is no max response time
-    trial.feedback_duration = trial.feedback_duration || 2000;
-
     display_element.innerHTML = '<div id="jspsych-categorize-html-stimulus" class="jspsych-categorize-html-stimulus">'+trial.stimulus+'</div>';
 
     // hide image after time if the timing parameter is set
diff --git a/plugins/jspsych-categorize-image.js b/plugins/jspsych-categorize-image.js
index 217960b2..5f59f68d 100644
--- a/plugins/jspsych-categorize-image.js
+++ b/plugins/jspsych-categorize-image.js
@@ -43,13 +43,13 @@ jsPsych.plugins['categorize-image'] = (function() {
       },
       correct_text: {
         type: jsPsych.plugins.parameterType.STRING,
-        default: 'Correct.',
+        default: "<p class='feedback'>Correct</p>",
         no_function: false,
         description: ''
       },
       incorrect_text: {
         type: jsPsych.plugins.parameterType.STRING,
-        default: 'Wrong.',
+        default: "<p class='feedback'>Incorrect</p>",
         no_function: false,
         description: ''
       },
@@ -79,7 +79,7 @@ jsPsych.plugins['categorize-image'] = (function() {
       },
       timeout_message: {
         type: jsPsych.plugins.parameterType.STRING,
-        default: 'Please respond faster.',
+        default: "<p>Please respond faster.</p>",
         no_function: false,
         description: ''
       },
@@ -106,21 +106,6 @@ jsPsych.plugins['categorize-image'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameters
-    trial.choices = trial.choices || jsPsych.ALL_KEYS;
-    trial.text_answer = (typeof trial.text_answer === 'undefined') ? "" : trial.text_answer;
-    trial.correct_text = (typeof trial.correct_text === 'undefined') ? "<p class='feedback'>Correct</p>" : trial.correct_text;
-    trial.incorrect_text = (typeof trial.incorrect_text === 'undefined') ? "<p class='feedback'>Incorrect</p>" : trial.incorrect_text;
-    trial.show_stim_with_feedback = (typeof trial.show_stim_with_feedback === 'undefined') ? true : trial.show_stim_with_feedback;
-    trial.force_correct_button_press = (typeof trial.force_correct_button_press === 'undefined') ? false : trial.force_correct_button_press;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? '' : trial.prompt;
-    trial.show_feedback_on_timeout = (typeof trial.show_feedback_on_timeout === 'undefined') ? false : trial.show_feedback_on_timeout;
-    trial.timeout_message = trial.timeout_message || "<p>Please respond faster.</p>";
-    // timing params
-    trial.stimulus_duration = trial.stimulus_duration || -1; // default is to show image until response
-    trial.trial_duration = trial.trial_duration || -1; // default is no max response time
-    trial.feedback_duration = trial.feedback_duration || 2000;
-
     display_element.innerHTML = '<img id="jspsych-categorize-image-stimulus" class="jspsych-categorize-image-stimulus" src="'+trial.stimulus+'"></img>';
 
     // hide image after time if the timing parameter is set
diff --git a/plugins/jspsych-external-html.js b/plugins/jspsych-external-html.js
index 28c1c63f..4683480b 100644
--- a/plugins/jspsych-external-html.js
+++ b/plugins/jspsych-external-html.js
@@ -34,7 +34,7 @@ jsPsych.plugins['external-html'] = (function() {
       },
       check_fn: {
         type: jsPsych.plugins.parameterType.FUNCTION,
-        default: 'function() { return true; }',
+        default: function() { return true; },
         no_function: false,
         description: ''
       },
@@ -49,11 +49,6 @@ jsPsych.plugins['external-html'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameters
-    trial.check_fn = trial.check_fn || function() { return true; }
-    trial.force_refresh = (typeof trial.force_refresh === 'undefined') ? false : trial.force_refresh
-
-
     var url = trial.url;
     if (trial.force_refresh) {
       url = trial.url + "?time=" + (new Date().getTime());
diff --git a/plugins/jspsych-free-sort.js b/plugins/jspsych-free-sort.js
index fa63c60c..1c18e0e6 100644
--- a/plugins/jspsych-free-sort.js
+++ b/plugins/jspsych-free-sort.js
@@ -72,15 +72,6 @@ jsPsych.plugins['free-sort'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default values
-    trial.stim_height = trial.stim_height || 100;
-    trial.stim_width = trial.stim_width || 100;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? '' : trial.prompt;
-    trial.prompt_location = trial.prompt_location || "above";
-    trial.sort_area_width = trial.sort_area_width || 800;
-    trial.sort_area_height = trial.sort_area_height || 800;
-    trial.button_label = typeof trial.button_label === 'undefined' ? 'Done' : trial.button_label;
-
     var start_time = (new Date()).getTime();
 
     var html = "";
diff --git a/plugins/jspsych-fullscreen.js b/plugins/jspsych-fullscreen.js
index 28684f17..9665a9c3 100644
--- a/plugins/jspsych-fullscreen.js
+++ b/plugins/jspsych-fullscreen.js
@@ -46,11 +46,6 @@ jsPsych.plugins.fullscreen = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    trial.fullscreen_mode = typeof trial.fullscreen_mode === 'undefined' ? true : trial.fullscreen_mode;
-    trial.message = trial.message || '<p>The experiment will switch to full screen mode when you press the button below</p>';
-    trial.button_label = trial.button_label || 'Go';
-    trial.delay_after = trial.delay_after || 1000;
-
     // check if keys are allowed in fullscreen mode
     var keyboardNotAllowed = typeof Element !== 'undefined' && 'ALLOW_KEYBOARD_INPUT' in Element;
     if (keyboardNotAllowed) {
diff --git a/plugins/jspsych-html-button-response.js b/plugins/jspsych-html-button-response.js
index 881cbef8..7ba272ab 100644
--- a/plugins/jspsych-html-button-response.js
+++ b/plugins/jspsych-html-button-response.js
@@ -42,6 +42,18 @@ jsPsych.plugins["html-button-response"] = (function() {
         no_function: false,
         description: ''
       },
+      margin_vertical: {
+        type: jsPsych.plugins.parameterType.STRING,
+        default: '0px',
+        no_function: false,
+        description: ''
+      },
+      margin_horizontal: {
+        type: jsPsych.plugins.parameterType.STRING,
+        default: '8px',
+        no_function: false,
+        description: ''
+      },
       stimulus_duration: {
         type: jsPsych.plugins.parameterType.INT,
         default: -1,
@@ -65,15 +77,6 @@ jsPsych.plugins["html-button-response"] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default trial parameters
-    trial.button_html = trial.button_html || '<button class="jspsych-btn">%choice%</button>';
-    trial.response_ends_trial = (typeof trial.response_ends_trial === 'undefined') ? true : trial.response_ends_trial;
-    trial.stimulus_duration = trial.stimulus_duration || -1; // if -1, then show indefinitely
-    trial.trial_duration = trial.trial_duration || -1; // if -1, then wait for response forever
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-    trial.margin_vertical = trial.margin_vertical || "0px";
-    trial.margin_horizontal = trial.margin_horizontal || "8px";
-
     // display stimulus
     display_element.innerHTML = '<div id="jspsych-html-button-response-stimulus">'+trial.stimulus+'</div>';
 
diff --git a/plugins/jspsych-html-keyboard-response.js b/plugins/jspsych-html-keyboard-response.js
index a0a5dcc1..5d987689 100644
--- a/plugins/jspsych-html-keyboard-response.js
+++ b/plugins/jspsych-html-keyboard-response.js
@@ -60,13 +60,6 @@ jsPsych.plugins["html-keyboard-response"] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // set default values for the parameters
-    trial.choices = trial.choices || jsPsych.ALL_KEYS;
-    trial.response_ends_trial = (typeof trial.response_ends_trial == 'undefined') ? true : trial.response_ends_trial;
-    trial.stimulus_duration = trial.stimulus_duration || -1;
-    trial.trial_duration = trial.trial_duration || -1;
-    trial.prompt = trial.prompt || "";
-
     var new_html = '<div id="jspsych-html-keyboard-response-stimulus">'+trial.stimulus+'</div>';
 
     // add prompt
diff --git a/plugins/jspsych-html-slider-response.js b/plugins/jspsych-html-slider-response.js
index 45ee5236..65b543a9 100644
--- a/plugins/jspsych-html-slider-response.js
+++ b/plugins/jspsych-html-slider-response.js
@@ -43,7 +43,7 @@ jsPsych.plugins['html-slider-response'] = (function() {
       },
       labels: {
         type: jsPsych.plugins.parameterType.KEYCODE,
-        default: [],
+        default: undefined,
         array: true,
         no_function: false,
         description: ''
@@ -84,17 +84,6 @@ jsPsych.plugins['html-slider-response'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    trial.min = trial.min || 0;
-    trial.max = trial.max || 100;
-    trial.step = trial.step || 1;
-    trial.labels = trial.labels || [];
-    trial.button_label = typeof trial.button_label === 'undefined' ? 'Next' : trial.button_label;
-    trial.response_ends_trial = (typeof trial.response_ends_trial == 'undefined') ? true : trial.response_ends_trial;
-    trial.stimulus_duration = trial.stimulus_duration || -1;
-    trial.trial_duration = trial.trial_duration || -1;
-    trial.prompt = trial.prompt || "";
-
-  
     var html = '<div id="jspsych-html-slider-response-wrapper" style="margin: 100px 0px;">';
     html += '<div id="jspsych-html-slider-response-stimulus">' + trial.stimulus + '</div>';
     html += '<div class="jspsych-html-slider-response-container" style="position:relative;">';
diff --git a/plugins/jspsych-iat-html.js b/plugins/jspsych-iat-html.js
index 1d6ea570..2ab79be6 100644
--- a/plugins/jspsych-iat-html.js
+++ b/plugins/jspsych-iat-html.js
@@ -104,21 +104,6 @@
 
   plugin.trial = function(display_element, trial) {
 
-    // set default values for the parameters
-    trial.left_category_key = trial.left_category_key || 'E';
-    trial.right_category_key = trial.right_category_key || 'I';
-    trial.left_category_label = trial.left_category_label || ['left'];
-    trial.right_category_label = trial.right_category_label || ['right'];
-    trial.key_to_move_forward = trial.key_to_move_forward || jsPsych.ALL_KEYS;
-    trial.display_feedback = typeof trial.display_feedback == 'undefined' ? false : trial.display_feedback;
-    trial.html_when_wrong = trial.html_when_wrong || '<span style="color: red; font-size: 80px">X</span>';
-    trial.bottom_instructions = trial.bottom_instructions || "<p>If you press the wrong key, a red X will appear. Press any key to continue.</p>";
-    trial.force_correct_key_press = trial.force_correct_key_press || false; //If true, key_to_move_forward is no longer needed
-    trial.stim_key_association = trial.stim_key_association || 'undefined';
-    trial.response_ends_trial = (typeof trial.response_ends_trial == 'undefined') ? true : trial.response_ends_trial;
-    trial.trial_duration = trial.trial_duration || -1;
-    trial.key_to_move_forward = trial.key_to_move_forward || jsPsych.ALL_KEYS;
-
     var html_str = "";
 
     html_str += "<div style='position: absolute; height: 20%; width: 100%; margin-left: auto; margin-right: auto; top: 42%; left: 0; right: 0'><p id='jspsych-iat-stim'>" + trial.stimulus + "</p></div>";
diff --git a/plugins/jspsych-iat-image.js b/plugins/jspsych-iat-image.js
index 66991a25..446d912e 100644
--- a/plugins/jspsych-iat-image.js
+++ b/plugins/jspsych-iat-image.js
@@ -106,21 +106,6 @@
 
   plugin.trial = function(display_element, trial) {
 
-    // set default values for the parameters
-    trial.left_category_key = trial.left_category_key || 'E';
-    trial.right_category_key = trial.right_category_key || 'I';
-    trial.left_category_label = trial.left_category_label || ['left'];
-    trial.right_category_label = trial.right_category_label || ['right'];
-    trial.key_to_move_forward = trial.key_to_move_forward || jsPsych.ALL_KEYS;
-    trial.display_feedback = typeof trial.display_feedback == 'undefined' ? false : trial.display_feedback;
-    trial.html_when_wrong = trial.html_when_wrong || '<span style="color: red; font-size: 80px">X</span>';
-    trial.bottom_instructions = trial.bottom_instructions || "<p>If you press the wrong key, a red X will appear. Press any key to continue.</p>";
-    trial.force_correct_key_press = trial.force_correct_key_press || false; //If true, key_to_move_forward is no longer needed
-    trial.stim_key_association = trial.stim_key_association || 'undefined';
-    trial.response_ends_trial = (typeof trial.response_ends_trial == 'undefined') ? true : trial.response_ends_trial;
-    trial.trial_duration = trial.trial_duration || -1;
-    trial.key_to_move_forward = trial.key_to_move_forward || jsPsych.ALL_KEYS;
-
     var html_str = "";
 
     html_str += "<div style='position: absolute; height: 20%; width: 100%; margin-left: auto; margin-right: auto; top: 42%; left: 0; right: 0'><img src='"+trial.stimulus+"' id='jspsych-iat-stim'></img></div>";
diff --git a/plugins/jspsych-image-button-response.js b/plugins/jspsych-image-button-response.js
index 1c4bd508..27b5db53 100644
--- a/plugins/jspsych-image-button-response.js
+++ b/plugins/jspsych-image-button-response.js
@@ -56,6 +56,18 @@ jsPsych.plugins["image-button-response"] = (function() {
         no_function: false,
         description: ''
       },
+      margin_vertical: {
+        type: jsPsych.plugins.parameterType.STRING,
+        default: '0px',
+        no_function: false,
+        description: ''
+      },
+      margin_horizontal: {
+        type: jsPsych.plugins.parameterType.STRING,
+        default: '8px',
+        no_function: false,
+        description: ''
+      },  
       response_ends_trial: {
         type: jsPsych.plugins.parameterType.BOOL,
         default: true,
@@ -74,15 +86,6 @@ jsPsych.plugins["image-button-response"] = (function() {
       console.error('Required parameter "stimulus" missing in image-button-response');
     }
 
-    // default trial parameters
-    trial.button_html = trial.button_html || '<button class="jspsych-btn">%choice%</button>';
-    trial.response_ends_trial = (typeof trial.response_ends_trial === 'undefined') ? true : trial.response_ends_trial;
-    trial.stimulus_duration = trial.stimulus_duration || -1; // if -1, then show indefinitely
-    trial.trial_duration = trial.trial_duration || -1; // if -1, then wait for response forever
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-    trial.margin_vertical = trial.margin_vertical || "0px";
-    trial.margin_horizontal = trial.margin_horizontal || "8px";
-
     // display stimulus
     var html = '<img src="'+trial.stimulus+'" id="jspsych-image-button-response-stimulus"></img>';
 
diff --git a/plugins/jspsych-image-slider-response.js b/plugins/jspsych-image-slider-response.js
index 18bb1eb0..2182b4f2 100644
--- a/plugins/jspsych-image-slider-response.js
+++ b/plugins/jspsych-image-slider-response.js
@@ -86,17 +86,6 @@ jsPsych.plugins['image-slider-response'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-
-    trial.min = trial.min || 0;
-    trial.max = trial.max || 100;
-    trial.step = trial.step || 1;
-    trial.labels = trial.labels || [];
-    trial.button_label = typeof trial.button_label === 'undefined' ? 'Next' : trial.button_label;
-    trial.response_ends_trial = (typeof trial.response_ends_trial == 'undefined') ? true : trial.response_ends_trial;
-    trial.stimulus_duration = trial.stimulus_duration || -1;
-    trial.trial_duration = trial.trial_duration || -1;
-    trial.prompt = trial.prompt || "";
-
     var html = '<div id="jspsych-image-slider-response-wrapper" style="margin: 100px 0px;">';
     html += '<div id="jspsych-image-slider-response-stimulus"><img src="' + trial.stimulus + '"></div>';
     html += '<div class="jspsych-image-slider-response-container" style="position:relative;">';
diff --git a/plugins/jspsych-instructions.js b/plugins/jspsych-instructions.js
index 48b9e938..02044fd8 100644
--- a/plugins/jspsych-instructions.js
+++ b/plugins/jspsych-instructions.js
@@ -71,14 +71,6 @@ jsPsych.plugins.instructions = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    trial.key_forward = trial.key_forward || 'rightarrow';
-    trial.key_backward = trial.key_backward || 'leftarrow';
-    trial.allow_backward = (typeof trial.allow_backward === 'undefined') ? true : trial.allow_backward;
-    trial.allow_keys = (typeof trial.allow_keys === 'undefined') ? true : trial.allow_keys;
-    trial.show_clickable_nav = (typeof trial.show_clickable_nav === 'undefined') ? false : trial.show_clickable_nav;
-    trial.button_label_previous = (typeof trial.button_label_previous === 'undefined') ? 'Previous' : trial.button_label_previous;
-    trial.button_label_next = (typeof trial.button_label_next === 'undefined') ? 'Next' : trial.button_label_next;
-
     var current_page = 0;
 
     var view_history = [];
diff --git a/plugins/jspsych-reconstruction.js b/plugins/jspsych-reconstruction.js
index f4403a70..91c23476 100644
--- a/plugins/jspsych-reconstruction.js
+++ b/plugins/jspsych-reconstruction.js
@@ -59,13 +59,6 @@ jsPsych.plugins['reconstruction'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameter values
-    trial.starting_value = (typeof trial.starting_value == 'undefined') ? 0.5 : trial.starting_value;
-    trial.step_size = trial.step_size || 0.05;
-    trial.key_increase = trial.key_increase || 'h';
-    trial.key_decrease = trial.key_decrease || 'g';
-    trial.button_label = typeof trial.button_label === 'undefined' ? 'Next' : trial.button_label;
-
     // if any trial variables are functions
     // this evaluates the function and replaces
     // it with the output of the function
diff --git a/plugins/jspsych-resize.js b/plugins/jspsych-resize.js
index bda3d25b..bb88171c 100644
--- a/plugins/jspsych-resize.js
+++ b/plugins/jspsych-resize.js
@@ -57,14 +57,6 @@ jsPsych.plugins["resize"] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default trial paramters
-    trial.item_height = trial.item_height || 1;
-    trial.item_width = trial.item_width || 1;
-    trial.prompt = trial.prompt || ' ';
-    trial.pixels_per_unit = trial.pixels_per_unit ||  100;
-    trial.starting_size = trial.starting_size || 100;
-    trial.button_label = trial.button_label || "Done";
-
     var aspect_ratio = trial.item_width / trial.item_height;
 
     // variables to determine div size
diff --git a/plugins/jspsych-same-different-html.js b/plugins/jspsych-same-different-html.js
index b1cbaf14..7055fd17 100644
--- a/plugins/jspsych-same-different-html.js
+++ b/plugins/jspsych-same-different-html.js
@@ -71,15 +71,6 @@ jsPsych.plugins['same-different-image'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameters
-    trial.same_key = trial.same_key || 81; // default is 'q'
-    trial.different_key = trial.different_key || 80; // default is 'p'
-    trial.advance_key = trial.advance_key || jsPsych.ALL_KEYS
-    trial.first_stim_duration = trial.first_stim_duration || 1000; // if -1, the first stim is shown until any key is pressed
-    trial.second_stim_duration = trial.second_stim_duration || 1000; // if -1, then second stim is shown until response.
-    trial.gap_duration = trial.gap_duration || 500;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-
     display_element.innerHTML = '<div class="jspsych-same-different-stimulus">'+trial.stimuli[0]+'</div>';
 
     var first_stim_info;
diff --git a/plugins/jspsych-same-different-image.js b/plugins/jspsych-same-different-image.js
index f9567f32..09e10001 100644
--- a/plugins/jspsych-same-different-image.js
+++ b/plugins/jspsych-same-different-image.js
@@ -62,6 +62,13 @@ jsPsych.plugins['same-different-image'] = (function() {
         no_function: false,
         description: ''
       },
+      advance_key: {
+        type: jsPsych.plugins.parameterType.KEYCODE,
+        array: true,
+        default: jsPsych.ALL_KEYS,
+        no_function: false,
+        description: ''
+      },
       prompt: {
         type: jsPsych.plugins.parameterType.STRING,
         default: '',
@@ -73,15 +80,6 @@ jsPsych.plugins['same-different-image'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameters
-    trial.same_key = trial.same_key || 81; // default is 'q'
-    trial.different_key = trial.different_key || 80; // default is 'p'
-    trial.advance_key = trial.advance_key || jsPsych.ALL_KEYS
-    trial.first_stim_duration = trial.first_stim_duration || 1000; // if -1, the first stim is shown until any key is pressed
-    trial.second_stim_duration = trial.second_stim_duration || 1000; // if -1, then second stim is shown until response.
-    trial.gap_duration = trial.gap_duration || 500;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-
     display_element.innerHTML = '<img class="jspsych-same-different-stimulus" src="'+trial.stimuli[0]+'"></img>';
 
     var first_stim_info;
diff --git a/plugins/jspsych-serial-reaction-time-mouse.js b/plugins/jspsych-serial-reaction-time-mouse.js
index 858522b2..63d58f45 100644
--- a/plugins/jspsych-serial-reaction-time-mouse.js
+++ b/plugins/jspsych-serial-reaction-time-mouse.js
@@ -16,13 +16,6 @@ jsPsych.plugins["serial-reaction-time-mouse"] = (function() {
     name: 'serial-reaction-time-mouse',
     description: '',
     parameters: {
-      grid: {
-        type: jsPsych.plugins.parameterType.BOOL,
-        array: true,
-        default: [[1,1,1,1]],
-        no_function: false,
-        description: ''
-      },
       target: {
         type: jsPsych.plugins.parameterType.INT,
         array: true,
@@ -30,6 +23,13 @@ jsPsych.plugins["serial-reaction-time-mouse"] = (function() {
         no_function: false,
         description: ''
       },
+      grid: {
+        type: jsPsych.plugins.parameterType.BOOL,
+        array: true,
+        default: [[1,1,1,1]],
+        no_function: false,
+        description: ''
+      },
       grid_square_size: {
         type: jsPsych.plugins.parameterType.INT,
         default: 100,
@@ -48,7 +48,7 @@ jsPsych.plugins["serial-reaction-time-mouse"] = (function() {
         no_function: false,
         description: ''
       },
-      timing_pre_target: {
+      pre_target_duration: {
         type: jsPsych.plugins.parameterType.INT,
         default: 0,
         no_function: false,
@@ -83,16 +83,6 @@ jsPsych.plugins["serial-reaction-time-mouse"] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    trial.grid = trial.grid || [[1,1,1,1]];
-    trial.grid_square_size = trial.grid_square_size || 100;
-    trial.target_color = trial.target_color || "#999";
-    trial.response_ends_trial = (typeof trial.response_ends_trial === 'undefined') ? true : trial.response_ends_trial;
-    trial.pre_target_duration = (typeof trial.pre_target_duration === 'undefined') ? 0 : trial.pre_target_duration;
-    trial.trial_duration = trial.trial_duration || -1; // if -1, then wait for response forever
-    trial.fade_duration = (typeof trial.fade_duration === 'undefined') ? -1 : trial.fade_duration;
-    trial.allow_nontarget_responses = (typeof trial.allow_nontarget_responses === 'undefined') ? false : trial.allow_nontarget_responses;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-
     var startTime = -1;
     var response = {
       rt: -1,
diff --git a/plugins/jspsych-serial-reaction-time.js b/plugins/jspsych-serial-reaction-time.js
index b0332967..b831076a 100644
--- a/plugins/jspsych-serial-reaction-time.js
+++ b/plugins/jspsych-serial-reaction-time.js
@@ -55,7 +55,7 @@ jsPsych.plugins["serial-reaction-time"] = (function() {
         no_function: false,
         description: ''
       },
-      timing_pre_target: {
+      pre_target_duration: {
         type: jsPsych.plugins.parameterType.INT,
         default: 0,
         no_function: false,
@@ -96,18 +96,6 @@ jsPsych.plugins["serial-reaction-time"] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    trial.grid = trial.grid || [[1,1,1,1]];
-    trial.choices = trial.choices || [['3','5','7','9']];
-    trial.grid_square_size = trial.grid_square_size || 100;
-    trial.target_color = trial.target_color || "#999";
-    trial.response_ends_trial = (typeof trial.response_ends_trial === 'undefined') ? true : trial.response_ends_trial;
-    trial.pre_target_duration = (typeof trial.pre_target_duration === 'undefined') ? 0 : trial.pre_target_duration;
-    trial.trial_duration = trial.trial_duration || -1; // if -1, then wait for response forever
-    trial.show_response_feedback = (typeof trial.show_response_feedback === 'undefined') ? false : trial.show_response_feedback;
-    trial.feedback_duration = (typeof trial.feedback_duration === 'undefined') ? 200 : trial.feedback_duration;
-    trial.fade_duration = (typeof trial.fade_duration === 'undefined') ? -1 : trial.fade_duration;
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-
     // create a flattened version of the choices array
     var flat_choices = jsPsych.utils.flatten(trial.choices);
     while(flat_choices.indexOf('') > -1){
diff --git a/plugins/jspsych-survey-likert.js b/plugins/jspsych-survey-likert.js
index 5daa5223..36e206a1 100644
--- a/plugins/jspsych-survey-likert.js
+++ b/plugins/jspsych-survey-likert.js
@@ -30,6 +30,12 @@ jsPsych.plugins['survey-likert'] = (function() {
         no_function: false,
         description: ''
       },
+      preamble: {
+        type: jsPsych.plugins.parameterType.STRING,
+        default: '',
+        no_function: false,
+        description: ''
+      },
       required: {
         type: jsPsych.plugins.parameterType.BOOL,
         array: true,
@@ -48,11 +54,6 @@ jsPsych.plugins['survey-likert'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameters for the trial
-    trial.preamble = typeof trial.preamble === 'undefined' ? "" : trial.preamble;
-    trial.required = typeof trial.required === 'undefined' ? false : trial.required;
-    trial.button_label = typeof trial.button_label === 'undefined' ? 'Next' : trial.button_label;
-
 
     var html = "";
     // inject CSS for trial
diff --git a/plugins/jspsych-survey-multi-choice.js b/plugins/jspsych-survey-multi-choice.js
index 871b7565..5e0a3e83 100644
--- a/plugins/jspsych-survey-multi-choice.js
+++ b/plugins/jspsych-survey-multi-choice.js
@@ -65,13 +65,6 @@ jsPsych.plugins['survey-multi-choice'] = (function() {
       return arr.join(separator = '-');
     }
 
-    // trial defaults
-    trial.preamble = typeof trial.preamble == 'undefined' ? "" : trial.preamble;
-    trial.required = typeof trial.required == 'undefined' ? null : trial.required;
-    trial.horizontal = typeof trial.required == 'undefined' ? false : trial.horizontal;
-    //If button_label is empty, the browser's language will be used to determine the button label.
-    trial.button_label = typeof trial.button_label === 'undefined' ? '' : trial.button_label;
-
     // inject CSS for trial
     display_element.innerHTML = '<style id="jspsych-survey-multi-choice-css"></style>';
     var cssstr = ".jspsych-survey-multi-choice-question { margin-top: 2em; margin-bottom: 2em; text-align: left; }"+
diff --git a/plugins/jspsych-survey-multi-select.js b/plugins/jspsych-survey-multi-select.js
index b4c78564..9dc591a8 100644
--- a/plugins/jspsych-survey-multi-select.js
+++ b/plugins/jspsych-survey-multi-select.js
@@ -63,14 +63,6 @@ jsPsych.plugins['survey-multi-select'] = (function() {
       return arr.join(separator = '-');
     }
 
-    // trial defaults
-    trial.preamble = typeof trial.preamble == 'undefined' ? "" : trial.preamble;
-    trial.required = typeof trial.required == 'undefined' ? false : trial.required;
-    trial.required_msg = trial.required_msg || '*please select at least one option!';
-    trial.horizontal = typeof trial.horizontal == 'undefined' ? false : trial.horizontal;
-    //If button_label is empty, the browser's language will be used to determine the button label.
-    trial.button_label = typeof trial.button_label === 'undefined' ? '' : trial.button_label;
-
 
     // inject CSS for trial
     display_element.innerHTML = '<style id="jspsych-survey-multi-select-css"></style>';
diff --git a/plugins/jspsych-survey-text.js b/plugins/jspsych-survey-text.js
index a1b3be7b..ed378f83 100644
--- a/plugins/jspsych-survey-text.js
+++ b/plugins/jspsych-survey-text.js
@@ -62,8 +62,6 @@ jsPsych.plugins['survey-text'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    trial.preamble = typeof trial.preamble == 'undefined' ? "" : trial.preamble;
-    trial.button_label = typeof trial.button_label === 'undefined' ? 'Next' : trial.button_label;
 
     if (typeof trial.rows == 'undefined') {
       trial.rows = [];
diff --git a/plugins/jspsych-video.js b/plugins/jspsych-video.js
index 9386224f..b2bac420 100644
--- a/plugins/jspsych-video.js
+++ b/plugins/jspsych-video.js
@@ -70,11 +70,6 @@ jsPsych.plugins.video = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // set default values for the parameters
-    trial.prompt = trial.prompt || "";
-    trial.autoplay = typeof trial.autoplay == 'undefined' ? true : trial.autoplay;
-    trial.controls = typeof trial.controls == 'undefined' ? false : trial.controls;
-
     // display stimulus
     var video_html = '<video id="jspsych-video-player" width="'+trial.width+'" height="'+trial.height+'" '
     if(trial.autoplay){
diff --git a/plugins/jspsych-visual-search-circle.js b/plugins/jspsych-visual-search-circle.js
index 8ead5d06..3cb613b4 100644
--- a/plugins/jspsych-visual-search-circle.js
+++ b/plugins/jspsych-visual-search-circle.js
@@ -57,14 +57,14 @@ jsPsych.plugins["visual-search-circle"] = (function() {
       target_size: {
         type: jsPsych.plugins.parameterType.INT,
         array: true,
-        default: 50,
+        default: [50, 50],
         no_function: false,
         description: ''
       },
       fixation_size: {
         type: jsPsych.plugins.parameterType.INT,
         array: true,
-        default: 16,
+        default: [16, 16],
         no_function: false,
         description: ''
       },
@@ -103,15 +103,6 @@ jsPsych.plugins["visual-search-circle"] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default values
-    trial.target_size = trial.target_size || [50, 50];
-    trial.fixation_size = trial.fixation_size || [16, 16];
-    trial.circle_diameter = trial.circle_diameter || 250;
-    trial.target_present_key = trial.target_present_key || 74;
-    trial.target_absent_key = trial.target_absent_key || 70;
-    trial.trial_duration = (typeof trial.trial_duration === 'undefined') ? -1 : trial.trial_duration;
-    trial.fixation_duration = (typeof trial.fixation_duration === 'undefined') ? 1000 : trial.fixation_duration;
-
     // circle params
     var diam = trial.circle_diameter; // pixels
     var radi = diam / 2;
diff --git a/plugins/jspsych-vsl-animate-occlusion.js b/plugins/jspsych-vsl-animate-occlusion.js
index dbc17d12..96bac2c2 100644
--- a/plugins/jspsych-vsl-animate-occlusion.js
+++ b/plugins/jspsych-vsl-animate-occlusion.js
@@ -78,16 +78,7 @@ jsPsych.plugins['vsl-animate-occlusion'] = (function() {
   }
 
   plugin.trial = function(display_element, trial) {
-
-    // default trial parameters
-    trial.cycle_duration = trial.cycle_duration || 1000;
-    trial.canvas_size = trial.canvas_size || [400, 400];
-    trial.image_size = trial.image_size || [100, 100];
-    trial.initial_direction = trial.initial_direction || "left";
-    trial.occlude_center = (typeof trial.occlude_center === 'undefined') ? true : trial.occlude_center;
-    trial.choices = trial.choices || jsPsych.ALL_KEYS;
-    trial.pre_movement_duration = (typeof trial.pre_movement_duration === 'undefined') ? 500 : trial.pre_movement_duration;
-
+    
     // variable to keep track of timing info and responses
     var start_time = 0;
     var responses = [];
diff --git a/plugins/jspsych-vsl-grid-scene.js b/plugins/jspsych-vsl-grid-scene.js
index 948608b7..ae90b2cc 100644
--- a/plugins/jspsych-vsl-grid-scene.js
+++ b/plugins/jspsych-vsl-grid-scene.js
@@ -46,11 +46,6 @@ jsPsych.plugins['vsl-grid-scene'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default parameter values
-    trial.image_size = trial.image_size || [100, 100];
-    trial.trial_duration = typeof trial.trial_duration === 'undefined' ? 2000 : trial.trial_duration;
-
-
     display_element.innerHTML = plugin.generate_stimulus(trial.stimuli, trial.image_size);
 
     jsPsych.pluginAPI.setTimeout(function() {
diff --git a/plugins/jspsych-xab-html.js b/plugins/jspsych-xab-html.js
index d394467f..f15a2d0c 100644
--- a/plugins/jspsych-xab-html.js
+++ b/plugins/jspsych-xab-html.js
@@ -69,16 +69,7 @@ jsPsych.plugins['xab-html'] = (function() {
   }
 
   plugin.trial = function(display_element, trial) {
-
-    // default trial values
-    trial.left_key = trial.left_key || 81; // defaults to 'q'
-    trial.right_key = trial.right_key || 80; // defaults to 'p'
-    trial.x_duration = trial.x_duration || 1000; // defaults to 1000msec.
-    trial.x_durationab_gap = trial.x_durationab_gap || 1000; // defaults to 1000msec.
-    trial.ab_duration = trial.ab_duration || -1; // defaults to -1, meaning infinite time on AB. If a positive number is used, then AB will only be displayed for that length.
-    trial.trial_duration = trial.trial_duration || -1; //
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-
+    
     // unpack the stimuli array
     trial.x_path = trial.stimuli[0];
 
diff --git a/plugins/jspsych-xab-image.js b/plugins/jspsych-xab-image.js
index 7f3067af..86b44377 100644
--- a/plugins/jspsych-xab-image.js
+++ b/plugins/jspsych-xab-image.js
@@ -72,15 +72,6 @@ jsPsych.plugins['xab-image'] = (function() {
 
   plugin.trial = function(display_element, trial) {
 
-    // default trial values
-    trial.left_key = trial.left_key || 81; // defaults to 'q'
-    trial.right_key = trial.right_key || 80; // defaults to 'p'
-    trial.x_duration = trial.x_duration || 1000; // defaults to 1000msec.
-    trial.x_durationab_gap = trial.x_durationab_gap || 1000; // defaults to 1000msec.
-    trial.ab_duration = trial.ab_duration || -1; // defaults to -1, meaning infinite time on AB. If a positive number is used, then AB will only be displayed for that length.
-    trial.trial_duration = trial.trial_duration || -1; //
-    trial.prompt = (typeof trial.prompt === 'undefined') ? "" : trial.prompt;
-
     // unpack the stimuli array
     trial.x_path = trial.stimuli[0];