Hello all,

I am trying to modify the Tower of London script so that it automatically computes all the variables I require. I have worked out how to do this for some variables, but am not sure how to approach this for time variables.

I want to compute three time variables (averages per item, summed over multiple attempts): average planning time, average subsequent/execution time and average solution time. So far, I have been able to calculate the total solution time for each item, summed over multiple attempts at that item. Therefore, I need to somehow sum the last line of this variable from the data, and divide by 12. Is there a way to sum the last line of a variable?

Similarly, for average planning time, I'll want to sum the first line of expressions.firstmovetime. For the subsequent/execution time, I assume I'll be able to easily subtract my planning average from my total average.

I hope this all makes sense. Any thoughts/direction would be greatly appreciated.

Thank you!

Nicola

To do this, you first need to stop thinking about the data in terms of "first" or "last" line. There is no way for Inquisit to "go back" through the data file while its running and look up those data points. The data file is just a static log of what happened. (Extracting those data points is a trivial exercise using a dedicated data analysis application, though). You, however, want a running computation on-the-fly, i.e., to get a given metric's average you need to (a) continuously update a sum of all relevant data points, (b) keep track of the relevant N and then (c) divide sum by N.

Hi Dave,

Thank you very much for your reply.

So in terms of the average solution time, I'm thinking I could introduce a variable (totalsolutiontime) which starts as zero (in <values taskparams> and <block test>), and under <trial feedback>, is specified as / ontrialbegin=[values.totalsolutiontime=values.totalsolutiontime+values.itemsolutiontime]. I would also include a variable (avesolutiontime) which is specified as values.totalsolutiontime/12 under <trial feedback> and zero under <values taskparams> and <block test>. Does this seem appropriate?

When it comes to planning time, I'm not sure how to approach this. I don't think I could do it in the same way as totalsolutiontime, under the <trial feedback>, because the value of firstmovetime at the <trial feedback> stage will be the firstmovetime of the most recent attempt at the item. I want the firstmovetime of the first attempt at the item. Do you have any suggestions of how to approach this?

Thank you!
Nicola

This would be one way to do it.

Look at *when exactly* firstmovetime is computed for each attempt by tracing the respective variables in the script. At that point, sum stuff up and store to a  new variable etc.

Hi Dave,

Thank you very much for your guidance! I think it's all worked out correctly now.

Nicola