Disaggregating
Data
Using
the Disaggregate function
The
DISAGGREGATE function in EZAnalyze allows you to summarize
your data by categories that are created by categorical
variables (glossary). Disaggregating
data is a critical part of the No Child Left Behind legislation
which is intended to close the "achievement gap" -
the differential academic performance of students according
to their ethnic background. The achievement gap is an excellent
example of disaggregated data, as it shows how different
students perform on standardized tests (the dependent variable)
according to which ethnic group they belong (the categorical
variable).
To disaggregate (glossary)
your data, select the "Disaggregate." option
from the EZAnalyze menu in Excel. "Double Disaggregation" is
also explained below.
When
the "Disaggregate" dialogue box appears, you will
see two boxes with a list of all of the variables in your
data set. The first box, labeled "Dependent variable(s)",
is where you choose which variables you want summarized.
You can choose one variable, or more than one. Some examples
of common dependent variables in school settings are GPA,
number of days absent, number of behavior referrals, and
standardized test scores.
The
second box, labeled "Categorical variable," is
where you select the variable that tells EZAnalyze about
your groups. This variable can be a numeric variable or
a string variable (glossary). You
can only select one categorical variable to disaggregate
your data by from this list, although you may choose a second
categorical variable to perform "Double Disaggregation",
which is explained below. Some examples of common categorical
variables in schools are ethnicity,
gender,
grade
level,
ELL status,
socioeconomic status, and learning disability status.
OPTIONS:
- Once
you have selected your dependent and categorical variables,
you can then select descriptive
statistic options located under the heading "statistic
reported." The N is generated by default. Your
options are:
| Mean |
For
each selected dependent variable, reports the average
for each group contained in the categorical variable |
| Median |
For
each selected dependent variable, reports the value for
each group contained in the categorical variable that
falls halfway between the highest score and the lowest
score |
| Minimum
value |
For
each selected dependent variable, reports what the lowest
number is for each group contained in the categorical
variable |
| Maximum
value |
For
each selected dependent variable, reports what the highest
number is for each group contained in the categorical
variable |
| Standard
deviation |
For
each selected dependent variable, reports how far on
average each score deviates from the mean for each group
contained in the categorical variable |
| Range |
For
each selected dependent variable, reports what the total
number of scores are (minimum value subtracted from maximum
value) for each group containted in the categorical variable |
- Double
Disaggregation -
place a check mark in the box next to "Then by categorical
variable 2" and select
your second categorical variable from the drop-down box.
When
you click OK, a results report will
be printed on a separate sheet for your review. (click
on "results report" for information on how to interpret
this analysis)
|