An independent samples t-test was conducted to compare perceptions of democracy in North Africa and Southern Africa using data from the 2015 Afrobarometer survey. The test revealed a statistically significant difference in perceptions between the two regions, with North African citizens reporting lower average levels of perceived democracy (M=4.44, SD=2.31) than Southern African citizens (M=5.31, SD=2.12), t(1083)=-6.36, p<0.001. This suggests that recent social movements in North Africa may have negatively impacted perceptions of democracy in that region relative to Southern Africa.

1. The t Test for Independent Samples
The t Test for Independent Samples
Program Transcript
MATT JONES: The independent samples t-test is a comparison
of means test
that compares two means across an independent categorical
variable. Let's go to

2. SPSS to see how we conduct this procedure. In my independent
sample t-test, I
would like to test for any possible differences between
socioeconomic status and
respondent's race. In SPSS in my Variable View for the race
variable, with the
label "What is respondent's race of first mention?," I can click
on the values. The
reason I'm doing this is because an independent sample t-test
can only test for
differences in two means at one time. Therefore, I can only
choose two races for
this test. I can see in the race variable that there are a number of
races present
within this variable.
For this test, I will choose respondents that self-identified as
white, which is
denoted as 1, and respondents to self-identified as black or
African American,
denoted as 2. I'll need to remember those for the next
procedure. To perform this
procedure, Analyze, Compare Means, independent sample t-test.
My test
variable is my dependent variable for the variable of which a
mean is calculated
on. Therefore, it is that metric level variable, or any other
variable where it makes
sense to calculate a mean. In this case, it's the socioeconomic
status index of the
respondent.
Click on that. Move it over to the test variable. The grouping
variable is my
categorical variable. And in this case, it is the respondent's
race. I move

3. respondents race over to the grouping variable. Right away,
behind the variable
name, you will see a set of parentheses with two question
marks. This is SPSS's
prompt to tell me what races I should enter. SPSS knows that it
can only
calculate two means and therefore is asking me to define
groups. So I must click
on the define groups, group 1 and group 2. For group 1, I'm
going to enter the
value number of 1, which were those respondents that self-
identified as white.
For group 2, I'm going to enter 2, which for those respondents
that self-identified
as black or African American. Click Continue, and once I click
OK, I will receive
the output for my independent sample t-test.
The first piece of output I'm provided are the group statistics. I
could look at the N
and get an idea of the sample that ended up in the test. There
are 1,094 white
respondents and 191 black or African American respondents. I
can see from the
descriptive statistics that the mean socioeconomic status index
score for whites
is 50.99, and for black or African Americans it's 44.96. I'm also
provided with
standard deviations for each mean, as well as the standard error
of the mean.
Before I interpret the independent sample t-test, I must first
examine the
Levene's test for equality of variances. An assumption of the
independent
samples t-test is that variances are equal across the two groups.

4. SPSS, by
default, provides you with this test to test for equality of
variances. There's an F
©2016 Laureate Education, Inc. 1
The t Test for Independent Samples
statistic, an associated p value with it. The Levene's test tests
the null hypothesis
that variances are equal. As you can see, the p value is 0.059,
which is slightly
above the conventional 0.050 threshold. In this case, you have
to make a
decision whether you reject or retain this null. If you set your
level of significance
at 0.050, and since 0.0059 is slightly above that, you would fail
to reject the null,
and assume equal variances.
Another option you might have is since this is so close to being
statistically

5. significant, you could also assume unequal variances, especially
since you have
an imbalance in the sample size above. For this specific test,
I'm going to choose
to interpret equal variances not assumed. As such, I interpret
the bottom row.
Here, I have a t statistic of 4.216, an associated p value of
0.000, which means
the results are statistically significant at the 0.001 level. The
mean difference
between white and black or African Americans, on average, is
6.02, with a 95%
confidence interval of the difference being between 3.21 and
8.84. Therefore, I
can safely reject the null hypothesis and conclude that there is a
significant
difference in socioeconomic status between those who identify
as white and
those who identify as black or African American.
©2016 Laureate Education, Inc. 2
© 2016 Laureate Education, Inc. Page 1 of 1
Week 6
Scenarios
1. As an international development researcher, you would like
to know African Citizen’s

6. perceptions about current levels of democracy. Your working
hypothesis is that a
series of reforms have increased African views of the level of
democracy today. You
do not have a good research design to compare attitudes before
and after the
reforms, but know that leaders and development experts would
like to see a value of
6, on the scale of 1–10. Using the data from the 2015
Afrobarometer, determine
whether perceptions about current levels of democracy
statistically differ from a
value of 6. Please provide: a 1–2 APA style paragraph statement
that furnishes an
answer to this question, note the relevant statistics, comment on
meaningfulness
and include your relevant SPSS output.
2. As an international development researcher, you have already
tested whether
perceptions about the current levels of democracy differ from a
value of 6. Given
recent social change movements in North Africa, you now want
to determine
whether there is a statistical difference in these perceptions
between North Africa
and Southern Africa. Using the data from the 2015
Afrobarometer, please provide: a
1–2 APA style paragraph statement that furnishes an answer to
this question, note
the relevant statistics, comment on meaningfulness, and include
your relevant SPSS
output.
3. As an educational researcher, would like to know whether
high school student’s

7. perceptions about mathematical utility changed between their
freshman and senior
year. Each respondent is asked the same series of questions
about the utility of
mathematics in their future during their freshman and senior
year. These questions
are combined to form one variable of mathematical utility;
higher values indicate
higher levels of mathematical utility. Using the High School
Longitudinal Survey,
please provide: a 1–2 APA style paragraph statement that
furnishes an answer to
this question, note the relevant statistics, comment on
meaningfulness, and include
your relevant SPSS output.