Measurement and Sampling
What is the level of measurement of gender?
Nominal
Why do we need to calculate intercoder reliability?
To ensure objectivity.
What is the cutoff of the p-value for a significant result?
p < 0.01 or p < 0.05 or p < 0.001
For T-test and ANOVA, the IV needs to be _____ measurement, and the DV needs to be _______.
IV: Nominal; DV: interval/ratio
For Chi-squared, the IV needs to be _____ (measurement level), and the DV needs to be _______. For Pearson's r, the IV needs to be _____ (measurement level), and the DV needs to be _______.
Chi-suqared: Nominal, Nominal
Pearson's r: interval/ratio, interval/ratio
What is the level of measurement of a 1 to 5 point scale?
Interval
What's the difference between a coding scheme vs a coding sheet?
Coding scheme: rule telling the coders how to code.
Coding sheets: the working sheet coders actually code.
What is confidence interval?
A range of values within which the population parameter is estimated to fall.
What is degree of freedom?
The number of observations that are free
to vary in calculating each statistic
Which statistical method requires your variables to be continuous variables?
Pearson's r
Why do we say a "true" probability sample only exists hypothetically?
Because we cannot guarantee that everybody has an equal chance to be selected in reality.
“Content analysis is a method of studying and analyzing communication in a systematic, objective, and quantitative manner for the purpose of measuring variables.”
Explain what systematic, objective, and quantitative mean.
Systematic: information to be analyzed selected using consistent rules
Objective: not biased by researcher’s idiosyncrasies
Quantitative: can be counted in mathematically meaningful way
What are type I and type II error?
Type I = false positive
Type II = false negative
What is the main difference between T-test and ANOVA?
T-test only tests two groups; ANOVA tests two or more groups.
What is the difference between cluster sampling and stratified sampling?
Cluster: identify naturally occurring clusters, randomly select one cluster, and randomly sample from it.
Stratified: develop strata of your population, and your sample should reflect that strata
How is content analysis different than qualitative textual analysis?
Content analysis: your concepts needs to be easily countable.
Qualitative textual analysis: your concepts rely more on your own interpretations.
In a normal distribution, what is the relationship between mean, mode, and median?
mean = mode = median
ANOVA is called analysis of variance because ______.
It examines the difference between within-group variation and between-group variation
How does Pearson's R work?
The correlation between two variables in terms how they change when the other changes, not causation.
Why do we want to aim for the "highest" level of measurement?
More statistical options; can always collapse down to lower levels.
How do we calculate percentage of agreenment?
total number of agreements/total number of reviews*100
What is the difference between standard deviation and standard error?
Standard deviation = how much individual value deviates from the mean of the sample
Standard error = how much the mean of a sample deviates from other samples' means
When we compare three groups, why should we use ANOVA instead of several T-tests comparing two groups every time (1 and 2, 2 and 3, 1 and 3)?
It inflates the possibility of type I error.
How does chi-squared work?
The deviation between observed and expected frequency.