Quiz 2 Flashcards
What two types of variables are there?
Independent and dependent
What determines the dependent variable?
Other variables in the study
What is the dependent variable?
The outcome of interest
What is the independent variable used to explain?
Outcome of interest (the dependent variable)
What is another name for the independent variable? Why?
Predictor variable because they’re used to predict the dependent variable
What does variance mean?
Diversity in data for a single variable
What does variance reflect?
How the values for a variable are dispersed.
What is standard deviation?
Square root of the variance.
What is distribution?
Refers to how the findings are dispersed.
What is frequency distribution?
The spread for how frequently each category occurs or is separated.
What are the mean, median, and mode most commonly used to measure?
Central tendency.
What is the mean?
Average of all values for a variable. Sum of all the values divided by the number of values.
What is mode?
Values that occurs most frequently.
Median?
Value that falls in the middle of the distribution when the numbers are in numeric order.
What is the alpha level most commonly set at?
0.05
If a p value >0.05 what does that mean?
There is no statistical significance of the results.
If a p value is <0.05 what does that mean?
There is statistical significance in the results.
What is a nominal variable?
No numbers. Example: yes/no.
What is an ordinal variable?
Variables in order. 1st, 2nd, 3rd place. Ranking order, do not tell anything else.
What is an interval variable? What is this type of variable commonly used for?
There are equal distances between variables on a tool or scale. Example: thermometer. Opinions/attitudes like preassigning numbers for pain rating.
What is a ratio variable?
Absolute 0. Either you have it or don’t have it. Each value has the same distance between the measures and has a true zero.
What is the most rigorous variable?
Ratio variable.
What variables are involved in parametric data? Assumption or no assumption about population?
Ratio, interval. Assumption about population.
What variables are involved in non-parametric data?
Nominal, ordinal. No assumption about population.
What are inferential statistics?
Trying to infer from the sample data what the population might think. Make judgements of the probability that an observed different between groups is reliable or happened by chance.
What is hypotheses testing?
Determine if there is enough evidence in a sample of data to infer that a certain condition is true for the entire population.
What is a population?
Larger group, all of the individuals that the researchers are interested in studying (adolescents)
What is a sample?
Subset of overall population that is included in a study.
What are the types of sampling for qualitative research?
Purposive sampling, convenience sampling, snowball sampling.
Purposive sampling?
Consists of participants who are intentionally or purposefully selected because they have certain characteristics related to the purpose of the research.
Convenience sampling?
Includes members of the population who can be readily found and recruited and are convenient for the researcher to recruit.
Snowball sampling?
Researcher will start with one participant or member of the population and will use that members contacts to identify other potential participants for the study and so on.
Generally, what is the sampling size in qual research?
<50
What does saturation mean?
Point in data collection at which the data becomes repetitive and no new information or participants is being added.
What is bias?
Occurs when some unintended factor confuses or changes the results in a way that can lead to incorrect conclusions
What approaches do non-probablility sampling use?
Approaches that don’t necessarily ensure everyone in the population of interest has a chance of being included in the study.
What types of sampling are included in non-probability sampling?
Convenience, purposive, quota, matched.
What is quota sampling?
Every member of the population doesn’t have equal chance to participate. One or more characteristics are identified that are important to the study and they’re used to establish limits/quotas on number of subjects included.
Non-probability vs probability sampling, which is more likely to have bias? What can we do to avoid it?
Non-prob. Random sampling.
Matched sample?
Researcher compares two groups to explain or understand something that differentiates them but knows that some other important characteristics could confused or bias understanding. Researcher selects subjects whose important characteristics are the same/matched.
What types of sampling are included in probability?
Simple random, stratified, cluster, systematic.
Simple random sampling?
All members of a population are identified and given a number, and from there randomly selected.
Stratified random sampling?
Population of interest divided into groups based on characteristics important to the study and then members within each group are randomly selected.
Cluster sampling?
Selecting groups that relate to the population of interest, then sampling smaller groups until eventually every individual subjects are selected.
Systematic sampling?
Members selected at intervals. Every 5th, or 10th member for example.
What does random assignment ensure?
All subjects have an equal chance of being in any particular group within the study.
What goal drives the sample size in quant research?
Generalizability