View source for Web-based perception experiments

Experiments can be hosted on the Department of Linguistics server, and then distributed to listeners by email link, or via Amazon Mechanical Turk.

An example is here: [http://linguistics.berkeley.edu/~kjohnson/talkers/memory.php?list=test example experiment]

A Javascript library [http://linguistics.berkeley.edu/~kjohnson/talkers/js/audexp.js audexp.js] makes it realatively easy to implement the following four kinds of typical experiment:

* Identification (id) - a single audio file is played, and a two-alternative forced choice (2AFC) is given.
* Discrimination (ax) - two audio files are played, and a 2AFC is given.
* Rating (r) - a single audio file is played, and a rating number (from 1 to 7) is given.
* Contrast Rating (cr) - two audio files are played, and a rating number is given.


Your html code must have four features:

* (1) after loading audexp.js, load a javascript file that defines 
** an array (or two arrays) of filenames that will be presented.
** a variable called 'block'
** here's an [http://linguistics.berkeley.edu/~kjohnson/talkers/js/blocktest_list.js example] of such a file
** this .js file was created with a small [http://linguistics.berkeley.edu/~kjohnson/talkers/js/make_wordlist.prl perl script] from a .csv spreadsheet.
** the html header contains these two lines to get the audexp.js library and the experiment-specific list of sound files.

  <script src="js/audexp.js"></script>
  <script src="js/blocktest_list.js"></script>

* (2) a call to load the experiment when the page is loaded
** this call specifies the type of experiment (in this case 'id')
** whether to randomize the order of presentation of the list of sound files
** the interstimulus interval for 'ax' and 'cr' types
** and the intertrial interval for all experiments.


  <body onload="load('id',false,500,2000);">

* (3) Three or for <span...> elements that will be used to give feedback to listeners.
 <span id="wr"></span>  is used to show warnings
 <span id="f1">sound 1</span>  is used to indicate that an audio file is playing 
 <span id="f2">sound 2</span>  is used to indicate that an audio file is playing 
 <span id="key">#</span> is used to indicate which key the listener pressed

* (4) A <form ...> element named "dataform" 
**the order of the input items determines the column order in the output file>
 <form method="POST" id="dataform" action="process.php?p=id&n=1">
      <input type="hidden" name="subject" value=<?php echo $subj; ?> />
      <input type="hidden" name="trial" />
      <input type="hidden" name="list" />
      <input type="hidden" name="file1" />
      <input type="hidden" name="filedur" />
      <input type="hidden" name="mystatus" />
      <input type="hidden" name="loadtime" />
      <input type="hidden" name="response" />
      <input type="hidden" name="rt" />
 </form>