PSPP, Review, Etc.
Class 9
Presentations
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Jennell
Danielle
Katie
Liz
• 2 historical/qualitative
brief “sharing” 
Correlation b/w Dichotomous and
Continuous Variables
• The point biserial
correlation coefficient, here
symbolized as rpb, pertains
to the case where one
variable is dichotomous and
the other is nondichotomous.
By convention, the
dichotomous variable is
treated as the X variable, its
two possible values being
coded as X=0 and X=1; and
the non-dichotomous
variable is treated as the Y
variable.
• http://vassarstats.net/pbcor
r.html
2 Way Factorial Designs (2 independent variables [often
one manipulated, one attribute)
2X2 (2 levels of both variables)
METHOD
Language
Classification
Traditional
Kodaly
Bilingual 1
Bilingual 2
Non-Bilingual 1
Non-Bilingual 2
Interpreting Results of 2x2 ANOVA
• (columns-main effect) Kodaly was more
effective than Traditional methods for both
bilingual and non-bilingual students
• (rows-main effect) Bilingual students scored
significantly higher than non-bilingual
students, regardless of teaching method
• Could be a significant interaction between
language and teaching method
– If there was significant interaction, we would need
to do post hoc Tukey or Sheffe do determine
where the differences lie.
Post Hoc (ANOVA to Tukey)
• Main Effects for LANG & METHOD
• Interaction b/w LANG & METHOD (treatment may have
only worked for one LANG group)
• BT < BK P<.01 (no surprise [m.e. for meth])
• BT < NBT P<.01 (no surprise [m.e. for lang])
• BT < NBLK P<.01 (no surprise [m.e. for meth & lang])
• NBLT = BK nonsignificant
• NBLT = NBLK nonsignificant (treatment only makes a
difference for bilingual students!!)
• BK < NBLK P<.01
PSPP
• Limited number of tests
• Accurate and fast
• Import CSV EXCEL files
– Comma delimited
• Surveys