Quant Qualifiers

Variable

an entity that can take a variety of different values. can be concrete or abstract.

conceptual definition of variable

written and clear definition of the concept. ex- communication apprehension is the fear or anxiety associated with either real or anticipated communication with others

operational definition of variable

describe the observable characteristics of a concept; how you plan to measure or “see” the concept. ex- on a scale of 1 (strongly disagree) to 5 (strongly agree) please rate your agreement with the following statement “I dislike participating in group discussions”.

Independent variable

the variable that influences or prompts a change in another variable (manipulated variable)

dependent variable

is influenced or changed by another variable (outcome seeking to observe)

nominal measurement

unordered categories with no true numerical values. ex- political party affiliation

ordinal measurement

ordered categories still without any clear numerical difference between levels. ex- top 25 NCAA teams

interval measurement

ordered categories where the categories are equally distant from one another but there’s no true numerical zero. ex Likert scale 1-5

ratio measurement

ordered categories where the categories are equally distant from one another and there is a true zero. ex- age, income

hypothesis

a statement that makes an educated guess about the relationship between an independent and a dependent variable. ex- sleep will be positively associated with academic performance.

null hypothesis

the opposite of the hypothesis. Indicates that there is no relationship between two variables. ex- there is no relationship between sleep and academic performance.

Survey

used to gather quantifiable data (numbers/trends) about a group of people through questions that ask people about their beliefs, values, attitudes, emotions, behavioral intentions, etc.

When should you use a survey?

When the variables can’t be changed. Ex- a person’s socioeconomic status.

What words indicate a survey should be used?

association and correlation

Experiment

researchers intentionally manipulate/change one or more independent variables to see how that variable affects other variables.

When should you use an experiment?

when examining a cause/effect relationship and a time order of these relationships. ex-messages of hope on student behavior.

Experiments have to be what?

randomly assigned

What is random assignment?

Experimenters assign the sample to experimental groups in a way that ensures everyone has an equal chance of being exposed to each experimental condition.

Chi-square test

Evaluate whether or not the observed frequencies differ from expected frequencies. Both variables are nominal. Ex- There will be an association between gender and class rank among those who take public speaking courses.

T-test

examines the association between one nominal variable (IV) and one interval/ratio (DV) variable. The nominal variable can only have 2 categories. Ex-men and women will differ in their levels of verbal aggression.

One-way ANOVA

examines the association between one nominal IV and one interval/ration DV. The nominal variable can have more than 2 categories. Ex-messages of hope will motivate more financial planning intentions than messages of fear or no message at all.

Correlations

determines the linear association between 2 interval/ratio variables. It’s purely a test of association not causation. Ex- greater level of job satisfaction will be associated with greater overall levels of life satisfaction.

Linear regression

Determines the linear association between 1 or more independent interval/ratio variables and 1 dependent interval/ratio variables. Can examine multiple IVs. more than one Test of association not causation. ex-public speaking anxiety will be negatively predicted by communication mindset and public speaking confidence.

What does p value mean?

the probability that two variables are related.

What p value is needed to find statistical significance?

.05

How can we tell whether probability is positive or negative?

r value