***  Notes - Discrimination Correct/Incorrect Report - Tetrad   ***


  TETRAD TESTING NOTES
  --------------------

    Tetrad Test is a discrimination test presenting 4 products to the judge among which 2 are from one group and 2 are from another group. 2A 2B.
    AABB BBAA ABAB BABA ABBA BAAB, 6 possible presentations, same as Triangle Test. 
    Guess probability is 33%, same as Triangle Test.  For the unspecified tetrad test.

      Unspecified tetrad test vs specified tetrad test.  More common type of tetrad test is the unspecified tetrad test.
        Unspecified tetrad test:
          Acccessors are not given any specific instructions about attributes to focus on.
          Acccessors task is simply to group the products with out regard for order or intensity.
          Guess probability is 33%, same as Triangle Test.
          SIMS Reports assume the unspecifed tetrad test.
        Specified tetrad test:
          Acccessors are given a specific attribute to focus on.
          Acccessors task is to group the products in the correct intensity order, usually low to high, week to strong, etc.
          Guess probability is 17%.  Adjust Excel line for 'Probability of a Correct Guess:', and recount correct/incorrect.


    Tetrad Test Setup:
      See examples on SIMS Webpage:  https://www.SIMS2000.com/Questionnaire-Tetrad.asp
        SIMS Software Express Package file examples are available on the webpage for quick Set up on your SIMS System.

      Your Affective SIMS Ballot must include:
        1 Instruction Box for the Group A and Group B Column headings, use <WEBTEXTGRID; Tag for this, copy from examples.
        4 Hedonics, 2 choices each, return values 1 and 2 referring to Group A and Group B.
        Each of the 4 Hedonic export labels  = "Relative Sample Order #" , where # is 1 to 4.
        Each of the 4 Hedonic questions text = "Sample <RELATIVE_SAMPLE_#_BLINDING_CODE>" , where # is 1 to 4.

        Only ONE Tetrad group of 4 can be built into the ballot.
          If you need multiple Tetrad groups then please use separate SIMS tests and use Test Linking for the panelist session.
          Reps, multiple Reps are supported.

      During your test, SIMS will be able to identify and detect the Tetrad Test page and validate the 2 x 2 responses for Group A & Group B.


    Tetrad special ballot detection criteria for Reports:
      In order to properly identify Tetrad Ballots and Tests,
      SIMS looks for ballots with exactly 4 Hedonics where Attribute Seen With = Relative Last Sample, and the Export Label contains word 'Relative'
      These guidelines are needed to best handle the new complexity of Tetrad designs and may be adjusted in the future.


    Tetrad Reports:
      Stats, same as Triangle Test.
        See complete statistical Table 17.8 Critical Number of Correct Responses in Triangle Test,
        Sensory Evaluation Techniques, 4th Edition, by Meilgaard, Civille, and Carr, page 433.

      Best SIMS Tetrad Report is located at:  SIMS Main Menu | Reports | Discrimination Reports | Discrimination Correct/Incorrect Report - Tetrad
      Most other SIMS reports will not provide meaningful information, please use the one report mentioned above.

      SIMS Reports assume the unspecifed tetrad test.


    Where's my Tetrad Test?:
      Likely your ballot didn't match the detection criteria discussed above.  Contact the Sensory Computer Systems support staff and they'll assist.


    Tetrad Experimental Design:
      Because this test is a little different than a typical discrimination test, the experimental design will also be a little different in setup.
      Two samples, four are presented.  Setup a 2C4R1 experimental design, with an experimental plan t=2, k=2, b=6, r=1 , where the 6 blocks are: 1) 1122 2) 2211 3) 1212 4) 2121 5) 1221 6) 2112.


    Tetrad Test Definition:
      Review your Test Rotation plan for accuracy.
 


   References: 

   IFT Webinar
   Tetrad Testing- How & Why - Sensory and Consumer Sciences Division | Tom Carr | March 2015
   https://www.pathlms.com/ift-learn-online/events/275/video_presentations/10871

   ASTM Standard E3009-15, developed by Committee E18.04, new standard as of June 2015.
   E3009 - Standard Test Method for Sensory Analysis-Tetrad Test

   ASTM WK WK32980 New Test Methods for Sensory Analysis-Tetrad Test
   Author: Tom Carr 2015

   GUIDING THE SWITCH FROM TRIANGLE TESTING TO TETRAD TESTING 
   Author: JOHN M. ENNIS, The Institute for Perception, Virgina USA, Published Journal of Sensory Studies June 2012 

   A LARGE-SCALE EXPERIMENTAL COMPARISON OF THE TETRAD AND TRIANGLE TESTS IN CHILDREN 
   Authors: KAREN GARCIA, JOHN M. ENNIS and WITOON RINYAWIWATKUL, Published Journal of Sensory Studies Aug 2012 



   Download:
   Fast track to a SIMS Tetrad test completely setup in your SIMS systsm via the SIMS software express package file: TETRAD.SIMS2000ExpressPackage.sql.ZIP