How can I define "no / null response" as correct?

[Adam Schadler]

Hi,

I have a series of trials that have a correct response coded as either "1" or "" (no quotes are actually entered).

For the trials with a correct response defined as "", I would like Trial.ACC to be 0 if a response was given and 1 if no buttons were pressed. How might I go about this?

So far, I have tried setting up the following experiment:

1.  Create a 10 item list, with a "correct" column
2. label 3rd, 5th, and 8th item with "1"
3. Run experiment.
   1. Enter "1" on 1st, 3rd, and 7th trials.

I would expect Trial.ACC for each trial to be:

1. 0
2. 1
3. 1
4. 1
5. 0
6. 1
7. 0
8. 0
9. 1
10. 1

However, Trial.ACC is actually this:

1. NULL
2. NULL
3. 1
4. NULL
5. NULL
6. NULL
7. NULL
   
8. NULL
   
9. NULL
   
10. NULL

Sincerely,

Adam Schadler