Block Course Test Prep Flashcards
What is exploratory research?
The goal of exploratory reserarch is connect ideas to understand cause-effect. It provides potential relationship and relevant questions in order to focus on type 2 error.
What is observational research?
The systematic study of behaviour as it occurs in the natural environment.
What is confirmatory research?
The goal of confirmatory research is to confirm a pre-specified relationship. It uses hypothesis testing to find statistically significant results and focuses on Type 1 error.
What does randomising participants to conditions help to ensure?
It increase internal validity by reducing systematic bias between groups.
What is internal validity?
The extent to which a study establishes a trustworth cause-effect relationship between a treatment and an outcome. It depends largely on the procedures of a study and how rigorously it is performed.
What is external validity?
External validity refers to how well the outcome of a study can be expected to apply to other settings. In other words, how generalizable the findings are.
What is a continuous distribution?
A continous distribution descries the probailities of the possible values of a continuous random variable.
What is a lognormal distribution?
A lognormal distribution is a continuous probability distribution of a random variable whose logarithm is normally distributed.
What is a discrete distribution?
A discrete distribution describe the probability of occurrence of each value of a discrete random variable. A discrete random variable has countable values, such as a list of non-negative integers.
What does Massey’s Code of Responsible Research Conduct say about sharing data?
Research data should be made available to peers who wish to repeat or elaborate on the study, subject to requirments for privacy, confidentiality and intellectual property.
How would you reverse score an item?
You would recode each item score to the reverse. Alternatively you can take the highest response score, add one to it, and then subtract the original respone to give you the reversed score.
What is expectation-maximisation imputation?
An interative procedure which uses other variables to impute a value (expectation), then checks whether that is the value most likely (maximisation). If not, re-imputes a more likely value. This goes on until it reaches the most likely value.
What is multiple imputation?
A general approach to the problem of missing data. It aims to allow for the uncertainty about the missing data by creating several different plausbile imputed data sets and appropriately combining results obtained from each of them.
What is Type 1 error?
A false positive. When the null hypothesis is rejected but it is actuall true.
What does a P value tell you?
Describes the level of evidence against the null hypothesis. A small value, typically <0.05 indicates strong evidence that the null should be rejected.
What is an alpha level?
The probability of a type 1 error (false positive). You set this before analysing your data and a P-value below this will reflect a statistically significant result.
What is family-wise error rate?
The probability of making one or more false discoveries (type 1 error) when performing multiple hypotheses tests.
What does a 95% confidence interval tell you?
It defines a range of values that you can be 95% certain the population parameter falls within.
What is a beta level?
The probability of a type 2 error.
What is P-hacking?
Also known as data dredging, refers to the misuse of data analysis to find patterns in data that can be presented as statistically significant when n fact there is no real underlying effect.
What does pre-registration help to address?
It should limit the degree to which p-hacking occurs because you outline your data analysis method before collecting data. Less false positives should be published.
What is ordinary least squares in multiple regression?
It chooses the parameters of a linear function of a set of explanatory variable by the principle of least squares. Least squares minimizes the sum of squares of the difference between the observed dependent variable in the given data set and those predicted by the linear function.
What is Cronbach’s Alpha useful for?
A measure of internal consistency presented as a coefficient. It is calculated using the average covariance between item-pairs.
What is internal consistency?
Correlations between different items on the same tests. It measures whether several items that propose to measure the same general construct produce similar scores.
What does the R2 value in a regression formula mean?
It is the coefficient of determination. It is the proportion of the variance in the dependent variable that is predictable from the independent variable. It provides a measure of how well observed outcomes are replicated by the model, based on the proportion of total variation of outcomes explained by the model.
What is MANOVA?
Multivariate analysis of variance is a procedure for comparing multivariate sample means. It is used when there are two or more dependent variables. It helps to determine whether changes in independent variables have significant effects on the dependent variables.
What is multilevel modelling?
Statistical models of parameters that vary at more than one level. It is used when participants are organised at more than one level.
An example could be a model of student performance that contains measures for individual students as well as measures for classrooms within which the students are grouped.
What is a dummy variable?
A variable which takes the value of 0 or 1 to indicate the absence or presence of some categorical effect that may be expected to shift the outcome.
eg. 1 = male, 2 = female
What is homoscedasticity?
A sequence of random variables is homescedastic if all its random variables have the same finite variance. This is also known as homogeneity of variance.
What is an error term?
The residual variable produced by a statistical or mathematical model, which is created when the model does not fully represent the actual relationship between the independent variables and the dependent variables.
What does it mean when error terms are independent?
The error term should predict random error. If it is correlated with the independent variable, it is not independent from that variable. That systematic variation that is creating the correlation should be included in the regression model itself.
What is additivity?
The effect of one independent variable on the dependent variable does not depend on the value of another independent variable.
What is ANOVA?
Analysis of Variance - generally used to determine if there is statistically significant difference between means among 2 or more groups.
What is the difference between a moderating and mediating effect?
A moderator variable (eg. sex, race, class) influences the strength/direction of a relationship between an independnt and dependent variable. A mediator explains the relationship between the two variables.
What is logistic regression?
Logistic regression is used to predict two different types of dependent variables. The first is a dichotomous dependent variable. The seoncd is an ordinal dependent variable.
What does B0 stand for in a regression equation?
The Y intercept. It is the predicted value of Y when all predictors are held at zero. Also known as the constant.
What is an indirect effect?
An indirect is transmitted through one or more meditator variables. Contrast this to a direct effect which is transmitted through the independent variables.
What does β1 tell you in a regression equation?
The slope. It is the expected increase in Y for a one-unit increase in X1.
