Stats in Research Flashcards
What are statistics?
Set of procedures and rules (math) for reducing large masses of data to manageable proportions in order to draw conclusions from those data.
What are the 2 types of stats?
Descriptive and Inferential
What are descriptive statistics and an example?
Numbers that summarize a bunch of data ex) 31 is the Lottery’s most frequently drawn number.
What are inferential stats and an example?
Calculations that determine whether an independent variable has a certain effect-allow us to draw inferences about the IV ex) Children with better verbal skills at age 12 are more likely to experience drinking problems at age 24
What is a population?
The entire group to which we want to generalize our results
What are parameters?
Numerical values summarizing population data
What are sample statistics?
The subgroup of the population that we collect the data from. Summarize this data using statistics-not parameters.
What is random sampling?
Every member of the population has an equal chance to participate in the study.
What is convenience sampling?
Participants selected for their accessibility or ease of testing.
What are some issues with convenience sampling?
- Extent to which sample is representative of the population
- Sample statistics wants to be similar to the population parameter, or we can’t infer anything about the population from our results.
What is random selection vs random assignment?
Random selection-Everyone in the population being studied has an equal chance of being selected to participate in the study.
Random Assignment-Everyone in the study has an equal chance at being assigned to either group in the study.
What are statistics affected by?
- The type of data we collect
- Whether we are interested in differences or relationships
- Number of groups/variables we want to compare
- Measurement scale
What is continuous data?
AKA measurement or quantitative data. The result of any type of measurement- values confined by our unit of measurement (ex: height, weight, reading speed, IQ score).
What is categorical data?
AKA frequency or count data. A count of frequencies within a category. ex) number of females in a class, number of people who vote in the next election.
What are differences versus relations?
Differences-Does an IV cause differences between groups in terms of the DV? (do intoxicated people respond more aggressively than sober people)
Relations-Are two or more variables related? (is alcohol associated with aggression?)
What is affected when we make the groups we study larger?
- Conducting the study
- The procedures we use to analyse results
- The interpretation of these analyses
What is the nominal scale of measurement?
Lowest level of measurement, responses assigned to mutually exclusive categories, categories do not imply any type of ordering (ex: could not rank from highest to lowest, eye colour, food, profession etc).
What is the ordinal scale of measurement?
Responses can be ordered from highest to lowest. Can make no claims that the intervals between units are equal (ex: cannot say that the interval between “very dissatisfied” and “Somewhat satisfied” is the same as between “very satisfied and somewhat satisfied.” Typically measures a subjective belief/opinion (ex: rate your level of this. How satisfied were you with your service?)
What is the interval scale of measurement?
Responses can be ordered from highest to lowest, units separated by objectively equal intervals, has no true 0 point (is arbitrary) (ex: latitude, year, temperature).
What is the ratio scale of measurement?
Most informative scale, responses can be ordered from highest to lowest, units separated by objectively equal intervals, has a true 0 point (ex: weight, amount of money, time elapsed).
What is the difference between N and n? (notation)
N= total sample size n= number of participants per group X= set of scores for one variable. Add a second, it would be repped by Y.
