Interntial Statistics

1. When to use
Inferential -
Multivariate test?
Dr. Molly Joy
Professor and Head,
Department of Psychology ,
Kristu Jayanti College
Bangalore

2. Inferential Statistical
Tests
 Chi Square
 compares observed frequencies to expected
frequencies
 Eg :Is the distribution of gender and eating
behavior due to chance or is there a
difference between the gender on eating
behavior?

3. When -The chi-square
goodness of fit test
 The sampling method is simple random
method
 The population is at least ten times as large
as the sample.
 The variable under study is categorical
 The expected value of the of sample
observations in each number and level of the
variable is at least 5

4. Chi-Square Test for
Independence
When you have two categorical variable from a single
population.
It is used to find whether there is a significant
association between the two variables.
For example, survey, on eating behaiour might be
classified by gender (male or female) and eating
preference like vegetarian, non -vegetarian, eggarian .
Then we use a chi-square test for independence to
determine whether gender has an association to
eating preference.

5. t-test- two independent
groups
 check the differences between two groups on some
variable of interest
 the IV must have only two groups (girls / boys , sales /
marketing )
 e.g.: Do men and women differ in the number
of hours they sleep in a given period

6. t-test Paired sample
 the same sample or group under goes
different condition
 Example - the sleep pattern after and before
the Behaviour therapy

7. ANOVA
 To test the significance of group differences
between two or more groups
 the IV has two or more categories
 only determines that there is a difference
between groups, but doesn’t tell which is
different
 ex: Do the academic achievement scores differ
for low -, middle-, and high-income students?

8. ANCOVA
same as ANOVA, but adds control of one or
more covariates that may influence the DV
Example :Do Academic achievement scores
differ for low-, middle-, and high-income
students after controlling for urban/rural
setting ?

9. MANOVA
• Multivariate analysis of variance or
multiple analysis of variance –it is a
statistical test procedure for comparing
multivariate means of several groups.
• As a multivariate procedure, it is used
when there are two or more dependent
variables

10. MANOVA
 same as ANOVA, but we can study two or more
related Dependent variables
 ex: Does income and living conditions can affect
verbal achievement, numerical achievement, and
performance achievement among 10th grade
student's.

11. Correlation- bivariate
 Correlation coefficient is a mathematical index
that describes the direction and magnitude of
relationship.
 In education and Psychology, there are times
when one needs to know whether there
exists any relationship among the different
attributes or abilities of the individual or they
are independent of each other
 Example - number of Hours spent for studying
and academic achievement.

12. Linear Regression
 linear regression is a linear ,relationship
between a response variable DV and one or
more explanatory variables.
 The case of one explanatory variable is called
simple linear regression;
 more than one, the process is called multiple
linear regression

13. Linear Regression
 used with one independent variables and one
dependent variable used for prediction
 it identifies the best set of predictor variables
 you can enter many IVs and it tells you which are best
predictors by looking at all of them at the same time
 in sequential regression the computer adds the
variables one at a time based on the amount of
variance they account for
 e.g.:IV anxiety , alcohol use, peer pressure DV.
Aggression tendencies