HDFS 350 Final Exam Study Guide Flashcards
What are the major parts of a research article?
Title of project, abstract, introduction, methods, results, figures and tables, discussion, and references
What type of information is included in the abstract?
General overview of the entire study
What type of information is included in the introduction?
problem and importance
research questions
research hypothesis
research gap
past literature review
What type of information is included in the methods section?
participants: participant demographic, sample size, inclusion/exclusion criteria, recruitment and compensation
measures: description of surveys
procedures: time to finish study
stats plan: plan of statistical tests
What type of information is included in the results section?
Figures, p-value, correlation results and statistical results
What type of information is included in the discussion section?
limitations, future directions
conclusion and summary
How do you identify an independent and dependent variable in a research question?
the independent variable is the factor that is manipulated or changed by the researcher to observe its effect on the dependent variable
the independent variable is the “cause” and the dependent variable is the “effect.”
What should you include in a good difference question?
2 or more groups - If two or more groups show a significant difference in a variable/outcome
EX:Are parents and non-parents different in how much they use their cell phone while driving?
What should you include in a good associational question?
is there a significant association or relationship between two variables?
Have IV and DV, but it doesn’t matter which is which. Identify two variables instead
EX: Is there a relationship between age and time spent using a cell phone while driving?
What is a null hypothesis?
there is no difference/relationship in the data
What is an alternative hypothesis?
there is a difference/relationship in the data
How is the null hypothesis and the alternative hypothesis related?
The null hypothesis is the statement or claim being made (which we are trying to disprove) and the alternative hypothesis is the hypothesis that we are trying to prove and which is accepted if we have sufficient evidence to reject the null hypothesis
what is a p-value?
probability that the result was due to chance
what is an alpha value?
predetermined significance threshold
How are the p-value and alpha value related?
A study is statistically significant if the P value is less than the pre-specified alpha
what is nominal measurement?
name, numbers are only descriptive, categories
ex. sex, blood type, pregnancy status
what is an ordinal scale of measurement?
rank ordered categories
ex. stars of restaurant or hotel, 20 teams, order of race finish, cancer stage
what is an interval scale of measurement?
continuous; interval between values is known/equal
Differences in numbers represent real differences in the variable
ex. temperature in F or C, SAT/GRE/IQ scores
what is a ratio scale of measurement?
continuous; equal intervals; has meaningful zero (absence to the variable being measured)
e.g., length, time In seconds/minutes/hours/days, age, weight
Ratios are meaningful (twice as high; half as warm)
which scales of measurement methods are continuous?
interval and ratio
what scales if measurement methods are categorical?
nominal and ordinal
When should you create a difference question?
Only 2 groups
T-test
T-score: means of two groups/variability between groups
P-value
When should you create an association question?
3 or more groups
ANOVA
F-score: differences between groups/differences within groups
P-value
What are inferential statistics?
infer from the sample about the population
test hypothesis, draws conclusions
cannot tell us which one is correct
allow us to make inferences about the true differences in the population on the basis of the sample data
give us the probability that the difference between means (or the association) reflects random error rather than a real difference (or association)
can only tell us about probabilities in terms of our conclusions and results not certainties
what are descriptive statistics?
only describing current sample
describes sample, summary of the data
How are inferential and descriptive statistics different?
Descriptive statistics summarize the characteristics of a data set, like the mean or median, while inferential statistics use data from a sample to make predictions or inferences about a larger population
How do you determine is an effect is significant?
compare the “p-value” to a predetermined significance level (often set at 0.05);
if the p-value is less than the significance level, then the effect is considered statistically significant
What is a pilot study?
a test run of your study
why is a pilot study done
to test the feasibility of your study design
How do you determine if a distribution is normal?
visually inspect a histogram of the data to see if it resembles a bell curve (symmetrical with one peak) and compare the mean, median, and mode,
what cutoff value is used to determine if a distribution is normal?
a z-score of +/- 2
What are parametric statistics?
assume approximately normal distribution
a fixed set of parameters
what are non-parametric statistics?
do not require a normal distribution
a set of data analysis methods that make few or no assumptions about the distribution of the data being studied
What is the difference between parametric and nonparametric data?
parametric data refers to date that is assumed to follow a specific distribution where nonparametric does not make assumptions about the data
What are examples of parametric statistics?
t-test, ANOVA and person’s correlation
What are examples of nonparametric statistics?
Mann-Whitney U, Kruskal-Wallis H and Spearman Rho
What are the assumptions of parametric statistics?
the data is normally distributed or nearly normally distributed
the variances are equal across all groups
the samples are independent
the data is measured at least on an interval scale
What are the assumptions of nonparametric statistics?
the data should be obtained from a random sample representing the population of interest
each data point should be independent from the others
do not assume the data follows a specific distribution like the normal distribution
when do you use a nonparametric tests?
when the assumptions for parametric tests are not met and you are not confident that you will have normally distributed data
what are the required scales of measurement for a t-test?
interval and ratio
what are the required scales of measurement for a Mann-Whitney U test?
ordinal scale
what are the required scales of measurement for a ANOVA test?
dependent variable is measured on a continuous scale (interval or ratio)
independent variable is measured on a categorical scale (nominal or ordinal level)
what are the required scales of measurement for a Kruskal-Wallis H test?
ordinal scale
what are the required scales of measurement for a Pearson’s r correlation test?
interval or ratio scale
what are the required scales of measurement for a Spearmann rho correlation test?
ordinal scale
What are the required assumptions of a t-test?
data is randomly sampled from the population
the data is normally distributed
the data is continuous (interval or ratio scale)
the variances between groups are equal (homogeneity of variance)
What are the required assumptions of a Mann-Whitney U test?
independent samples: both groups being compared must be independently drawn from their respective populations, meaning observations within each group should not influence each other
ordinal data:the variable being measured should be at least on an ordinal scale, meaning data can be ranked from lowest to highest
What are the required assumptions of a ANOVA test?
normality (data within each group should be normally distributed)
homogeneity of variance (the variance of the data within each group should be equal)
independence (observations within each group should be independent of each other)