Unit 11 - Data handling and data analysis Flashcards
what is coding?
Coding means assigning a code, usually a number, to each possible response to each question.
what are the questions to be answered by the researcher?
1) How many variables to analyze?
a) Univariate
b) Bivariate
c) Multivariate
2) Which kind of conclusions do you want to reach?
a) Descriptive statistics
b) Inferential statistics
3) What type of primary scale of measurement?:
a) Nominal
b) Ordinal
c) Interval
d) Ratio
how many multivariate techniques are there?
- dependence technique
2. interdependence technique
objective of crosstabulation?
Determine the existence of a relationship between two or more variables
advantages of crosstabulation?
– Applicable to nominal data
– No assumption about the nature of the relationship
– Simple and easy to communicate
disadvantages of crosstabulation?
– Need at least 5 observations in each cell for reliability
– Requires skill (luck) to assign classes
– Sample sizes increases greatly with more complex analyses
what are the steps involved in hypothesis testing?
- Formulate H0 and H1
- Select Appropriate Test
- Choose Level of Significance
- Collect Data and Calculate Test Statistic
- Determine Probability Associated with Test Statistic
- 2.Determine Critical Value of Test Statistic TSCR
what is the p-value?
The p-value is the probability of getting the results you did (or more extreme results) given that the null hypothesis is true
• If p-value < 0.05 Reject H0
(strong evidence against the null hypothesis)
• If p-value > 0.05 No reject H0
how many hypothesis tests can we do?
- test of association
2. test of differences
comment on cross-tabulation in practice:
•Test the null hypothesis that there is no association between the variables using the chi-square statistic. If you fail to reject the null hypothesis, then there is no relationship.
•If H0 is rejected, then determine the strength of the
association using an appropriate statistic (phi-coefficient, contingency coefficient, or Cramer’s V), as discussed earlier.
what do parametric tests assume?
that the variables of interest are measured on at least an interval scale
in the context of hypothesis testing related to differences, when are the samples independent?
The samples are independent if they are drawn randomly from different populations.
when are the samples paired?
The samples are paired when the data for the two
samples relate to the same group of respondents.
what does the t-statistic assume?
The t-statistic assumes that the variable is normally
distributed and the mean is known (or assumed to be
known) and the population variance is estimated from
the sample
