|Date: ||Mon, 15 May 2006 09:09:50 +1000|
|Reply-To: ||Simon Freidin <firstname.lastname@example.org>|
|Sender: ||"SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>|
|From: ||Simon Freidin <email@example.com>|
|Subject: ||Re: counting valid reactions in a given time|
|Content-Type: ||text/plain; charset=US-ASCII; delsp=yes; format=flowed|
do repeat x=rt2 to rt10/y=1 to 9.
if rttot<=25 rttot=sum(rt1 to x).
if numclick=0 and rttot>25 numclick=y.
if numclick=0 numclick=nvalid(rt1 to rt10).
On 15/05/2006, at 7:40 AM, Philippe Rast wrote:
> Dear List
> We did a reaction-time experiment which ought to last 25 sec.
> People had
> to point on a certain dot and press the mouse button - for every
> answer the reaction was recorded. The idea was to count the clicks per
> 25 seconds.
> Now, something went wrong and the program sometimes did not stop after
> 25 seconds. So lots of subjects hade more time for the task and hence
> more clicks.
> Since I have the reaction times I could check, how many clicks were
> performed in the first 25 seconds. But how can I do this?
> data list free/rt1 to rt10.
> begin data
> 2, 3, 1, 2, 3, 2, 1, 4, 2, 3
> 5, 6, 4, 3, 5, , , , ,
> 4, 5, 7, 6, 5, 6, 4, 6, 7, 5,
> end data.
> comp sum=sum(rt1 TO rt10).
> variable label sum 'reaction times summed'.
> comp clicks=nvalid(rt1 TO rt10).
> Case one has reacted 10 times in 25 seconds, while case two has
> 5 times in 25 seconds.
> Now, case 3, has reacted 4 times in 25 seconds but the program did not
> stop and the person was allowed to click for 55 seconds. Now doing a
> NVALID gives me 10 - but in 55 seconds.
> I would like SPSS to start adding the rt's up to 25 seconds and then
> give me the number of variables added, so that case three would be 4.
> Has anyone an idea how to do this - in reality the rt's are
> measured in
> milliseconds and some of the 600 subjects clicked up to 550 times. The
> solution aught to be applicable in syntax :-) ?
> Thanks in advance!