<p>I wanted to report further findings in my search for the answer to this question. I will not accept this as the answer but I think anyone else who looks into this issue may find this information useful.</p>

<p>I obtained the original paper by Berg (1) published in 1948 in the journal of general psychology. The paper makes no explicit mention of why 4 stimulus cards are shown. Perhaps the choice was to follow previous methods in similar tests such as the Goldstein-Sheerer cube test (2). </p>

<p>The results of the Berg paper, a <em>post-hoc</em> style analysis, grouped the participants into 3 groups based on quantitative performance (A,B, and C). Group A quickly determined the rules of the test and performed well on the remainder of the test. Group B took longer and verbally reported trying many hypotheses of the rules before discovering there were 3 rules to choose from. Group C had no idea what was going on, some subjects perseverated 100 trials with their own incorrect rule. </p>

<p>I therefore speculate that if there were only 3 stimulus cards that group B would be somewhat eliminated. Subjects who could determine the rules would get there faster by elimination since there could only be 1 correct stimulus card at a time. One virtue then, of having 4 cards, is to parse out subjects who have a more keen ability to "think/shift" which could be more useful/powerful if the goal of the test is to quantify shifting ability.</p>

<p>Furthermore, I took the online test located <a href="http://www.psytoolkit.org/experiment-library/experiment_wcst.html" rel="nofollow">here</a> and found 18 out of 60 trials where there was more than 1 matching possibility yet I was able to succeed at the test because I was able to track which rule I had been using. </p>

<p>I agree with Robin Kramer that the number of stimulus cards can be altered depending on the purpose of the test.</p>

<blockquote>
  <ol>
  <li><p>"A simple objective technique for measuring flexibility in thinking." Berg, A, 1948, Journal of General Psychology, Vol 39,
  15-22.</p></li>
  <li><p>"Abstract and concrete behavior: An experimental study with special tests." Goldstein, K., Scheerer, M., 1941, Psychology Monologues, Vol
  53, 1-151</p></li>
  </ol>
</blockquote>

CC BY-SA 3.0
2016-07-27T20:48:30.173Z
Thank you for sharing this! There is no shame in accepting your own answer. you were the one finding the original paper ;)
Robin Kramer-ten Have
CC BY-SA 3.0
2016-07-28T14:58:58.973Z
I'll wait a little longer to see if anyone else has input then I'll accept answer
willpower2727
CC BY-SA 3.0
2016-07-27T19:48:55.980Z
2016-07-27T19:48:55.980Z
willpower2727
<p>I cannot tell you why they chose four cards, but I do know that it is perfectly fine to use three, (e.g. <a href="http://www.jneurosci.org.proxy-ub.rug.nl/content/35/21/8145.full#F1" rel="nofollow">Niv and colleagues, 2015</a>).</p>

<p>To give you more info on why the WCST is used in the study by Niv. The study wanted to see how you could best model learning (and relearning) multidimensional information, to be able to better understand how people make sense of the multidimensional information provided by the real world. Therefore, they had participants perform the WCST with three cards. Multiple reinforcement learning algorithms were then fitted to the behavioral data, and they found that a reinforcement learning model that includes decay (as to model memory decay) was best able to do so. </p>

<p>I believe it would have been perfectly fine to have used four cards in that study as well. It would make it more difficult to learn on which dimension to focus, which would probably also be modeled. </p>

<p>There are also variations of the WCST (e.g. <a href="http://www.ncbi.nlm.nih.gov/pubmed/25509823" rel="nofollow">Catherwood and colleagues, 2014</a>). In that study they instead of took apart four dimensions and showed a 2x2 matrix with each unit depicting a different dimension. </p>

<h2>In short</h2>

<p>Depending on the goal of your experiment, you can decide how you would like to use the WCST specifically. </p>

CC BY-SA 3.0
2016-07-25T22:43:50.497Z
+1 The original task most likely had 4 cards because there are - as you mention - 4 (2x2) scenarios.
Arnon Weinberg
CC BY-SA 3.0
2016-07-26T13:17:14.670Z
Thanks, I thought it would be ok to use 3. Just to be certain, I have requested the original 1948 paper on the WCST and once I am able to review it I'll report back.
willpower2727
CC BY-SA 3.0
2016-07-25T19:15:25.480Z
2016-07-26T06:16:07.903Z
2016-07-26T06:16:07.903Z
Robin Kramer-ten Have
<p>I've reviewed the papers by <a href="http://dx.doi.org/10.1037/h0059831" rel="nofollow">Grant, D. A., &amp; Berg, E. (1948)</a> and <a href="http://dx.doi.org/10.1037/h0061659" rel="nofollow">Fey, E. T. (1951)</a>.</p>

<p>These papers from what I was able to find, lay out the basis of the Wisconsin Card Sorting Test (WCST). There are three possible rules for sorting the cards; color, shape, or count. I am curious why the WCST places 4 stimulus cards in front of the patient when 3 carefully chosen cards would be sufficient. With 4 cards it seems that unless the examiner makes special preparations, there might be occasions when there is more than 1 correct stimulus card to choose, or during a transition from certain rule to the next the patient may make an incorrect guess and won't be able to tell which rule to eliminate.</p>

<p>Can anyone explain why there has to be 4 stimulus cards? Could I run an equally effective WCST with 3 stimulus cards?</p>

<p><sub>
Grant, D. A., &amp; Berg, E. (1948). <a href="http://dx.doi.org/10.1037/h0059831" rel="nofollow">A behavioral analysis of degree of reinforcement and ease of shifting to new responses in a Weigl-type card-sorting problem.</a> Journal of experimental psychology, 38(4), 404.<br>
Fey, E. T. (1951). <a href="http://dx.doi.org/10.1037/h0061659" rel="nofollow">The performance of young schizophrenics and young normals on the Wisconsin Card Sorting Test.</a> Journal of consulting psychology, 15(4), 311.<br>
</sub></p>

<test><categorisation><frontal-lobes>
Significance of 4 stimulus cards in the Wisconsin Card Sorting Test?
willpower2727
# Significance of 4 stimulus cards in the Wisconsin Card Sorting Test?

(Asked by: username_0 on 2016-07-25)

I've reviewed the papers by [Grant, D. A., & Berg, E. (1948)](http://dx.doi.org/10.1037/h0059831) and [Fey, E. T. (1951)](http://dx.doi.org/10.1037/h0061659).

These papers from what I was able to find, lay out the basis of the Wisconsin Card Sorting Test (WCST). There are three possible rules for sorting the cards; color, shape, or count. I am curious why the WCST places 4 stimulus cards in front of the patient when 3 carefully chosen cards would be sufficient. With 4 cards it seems that unless the examiner makes special preparations, there might be occasions when there is more than 1 correct stimulus card to choose, or during a transition from certain rule to the next the patient may make an incorrect guess and won't be able to tell which rule to eliminate.

Can anyone explain why there has to be 4 stimulus cards? Could I run an equally effective WCST with 3 stimulus cards?

Grant, D. A., & Berg, E. (1948). [A behavioral analysis of degree of reinforcement and ease of shifting to new responses in a Weigl-type card-sorting problem.](http://dx.doi.org/10.1037/h0059831) Journal of experimental psychology, 38(4), 404.  
Fey, E. T. (1951). [The performance of young schizophrenics and young normals on the Wisconsin Card Sorting Test.](http://dx.doi.org/10.1037/h0061659) Journal of consulting psychology, 15(4), 311.

**Tags:** test, categorisation, frontal-lobes


---

## 2 answers

### Answer by username_1 on 2016-07-25. Score: 4 | Accepted answer

I cannot tell you why they chose four cards, but I do know that it is perfectly fine to use three, (e.g. [Niv and colleagues, 2015](http://www.jneurosci.org.proxy-ub.rug.nl/content/35/21/8145.full#F1)).

To give you more info on why the WCST is used in the study by Niv. The study wanted to see how you could best model learning (and relearning) multidimensional information, to be able to better understand how people make sense of the multidimensional information provided by the real world. Therefore, they had participants perform the WCST with three cards. Multiple reinforcement learning algorithms were then fitted to the behavioral data, and they found that a reinforcement learning model that includes decay (as to model memory decay) was best able to do so.

I believe it would have been perfectly fine to have used four cards in that study as well. It would make it more difficult to learn on which dimension to focus, which would probably also be modeled.

There are also variations of the WCST (e.g. [Catherwood and colleagues, 2014](http://www.ncbi.nlm.nih.gov/pubmed/25509823)). In that study they instead of took apart four dimensions and showed a 2x2 matrix with each unit depicting a different dimension.

## In short

Depending on the goal of your experiment, you can decide how you would like to use the WCST specifically.

> **Comments:**
> **username_2**: +1 The original task most likely had 4 cards because there are - as you mention - 4 (2x2) scenarios.  
> **username_0**: Thanks, I thought it would be ok to use 3. Just to be certain, I have requested the original 1948 paper on the WCST and once I am able to review it I'll report back.  

---

### Answer by username_0 on 2016-07-27. Score: 1

I wanted to report further findings in my search for the answer to this question. I will not accept this as the answer but I think anyone else who looks into this issue may find this information useful.

I obtained the original paper by Berg (1) published in 1948 in the journal of general psychology. The paper makes no explicit mention of why 4 stimulus cards are shown. Perhaps the choice was to follow previous methods in similar tests such as the Goldstein-Sheerer cube test (2).

The results of the Berg paper, a *post-hoc* style analysis, grouped the participants into 3 groups based on quantitative performance (A,B, and C). Group A quickly determined the rules of the test and performed well on the remainder of the test. Group B took longer and verbally reported trying many hypotheses of the rules before discovering there were 3 rules to choose from. Group C had no idea what was going on, some subjects perseverated 100 trials with their own incorrect rule.

I therefore speculate that if there were only 3 stimulus cards that group B would be somewhat eliminated. Subjects who could determine the rules would get there faster by elimination since there could only be 1 correct stimulus card at a time. One virtue then, of having 4 cards, is to parse out subjects who have a more keen ability to "think/shift" which could be more useful/powerful if the goal of the test is to quantify shifting ability.

Furthermore, I took the online test located [here](http://www.psytoolkit.org/experiment-library/experiment_wcst.html) and found 18 out of 60 trials where there was more than 1 matching possibility yet I was able to succeed at the test because I was able to track which rule I had been using.

I agree with Robin Kramer that the number of stimulus cards can be altered depending on the purpose of the test.

> 1. "A simple objective technique for measuring flexibility in thinking." Berg, A, 1948, Journal of General Psychology, Vol 39,
>    15-22.
> 2. "Abstract and concrete behavior: An experimental study with special tests." Goldstein, K., Scheerer, M., 1941, Psychology Monologues, Vol
>    53, 1-151

> **Comments:**
> **username_1**: Thank you for sharing this! There is no shame in accepting your own answer. you were the one finding the original paper ;)  
> **username_0**: I'll wait a little longer to see if anyone else has input then I'll accept answer  

---

