Overwritten file recovery

[David McFarlane]

No.  That's why E-Prime asks you before it overwrites a data 
file.  Perhaps, on subject-running stations, we should develop the 
habit of never saying "Yes" to overwrite a data file (we could still 
overwrite for test runs on development workstations).  And never use 
Subject 1 Session 1 for a real run -- that is the default, and 
inevitably someone will use that for a quick test run and will 
overwrite existing data.

More detail:  E-Prime overwrites the .txt recovery file just about as 
soon as you say Yes, so already too late there.  But it does not 
write the .edat file until the end of the run.  So if you abort the 
run before the end you will still have the old data in the .edat file 
(and could use the .txt file to generate an .edat file from the new 
data).  Otherwise you are sunk.

Unless, of course, you have the sort of resources availabe to the 
National Security Agency of the United States of America.  According 
to what I have read, as long as you use magnetic media, the 
magnetization of each bit is a compendium of all previous writes to 
that bit, and even more information about past writes may be found 
slightly off the main track, so with sufficient resources one might 
actually recover overwritten data (that is why, when you really do 
want to make data unrecoverable, you need to do multiple overwrites 
with random data).  But it hardly seems worth that much effort to 
recover data from one subject run.

-----
David McFarlane
E-Prime training 
online:  http://psychology.msu.edu/Workshops_Courses/eprime.aspx
Twitter:  @EPrimeMaster (https://twitter.com/EPrimeMaster )

/----
Stock reminder:  1) I do not work for PST.  2) PST's trained staff 
take any and all questions at https://support.pstnet.com , and they 
strive to respond to all requests in 24-48 hours, so make full use of 
it.  3) In addition, PST offers several instructional videos on their 
YouTube channel (http://www.youtube.com/user/PSTNET ).  4) If you do 
get an answer from PST staff, please extend the courtesy of posting 
their reply back here for the sake of others.
\----


At 3/28/2014 04:49 PM Friday, p5wp1 wrote:
>I have been running participants in two versions of a program. I 
>accidentally mixed up the two versions (stupid me...) and overwrote 
>a good participant file. Specifically, I ran a participant under #4 
>a few days ago. Today, I ran another participant in the same program 
>and accidentally selected participant #4 again (that is, I clicked 
>'OK' when it asked if I wanted to overwrite/override the original 
>participant #4). I was wondering if there is any way to recover an 
>E-DataAid file or its accompanying text document once it has be overwritten.
>
>Thank you!

-- 
You received this message because you are subscribed to the Google Groups "E-Prime" group.
To unsubscribe from this group and stop receiving emails from it, send an email to e-prime+unsubscribe at googlegroups.com.
To post to this group, send email to e-prime at googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/e-prime/5339ba69.4131320a.6fc0.5532SMTPIN_ADDED_MISSING%40gmr-mx.google.com.
For more options, visit https://groups.google.com/d/optout.