what you do with extreme values is ok but ... that still does not say they were bad values
however, if you drop those who gain 2 sds below the mean gain ... then by same reasoning i think you have to drop those 2 sds above the mean gain ... since this decision is totally arbitrary
personally, unless you had corroborative evidence that the values were coded/scored/entered wrong ... i would leave them in ...
or, analyze it both ways and see if it really makes any difference
i don't give away data easily
At 10:36 PM 2/27/03 -0600, Harris, Betty A wrote:
Hi all,
While we're talking about outliers I had my first dose of looking at TerraNova data collected near the beginning of the school year and then again from the same kids near the end of the school year. We received NCE scores back on: Reading Composite Reading Subtest Vocabulary Subtest Word Analysis Subtest
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