In JASP, what is the purpose of the 'Split' box in the Descriptive Statistics analysis?
It is used to produce descriptive statistics and plots for each group defined by a categorical or ordinal grouping variable.
What statistical concept is a measurable characteristic of a population, such as a mean or standard deviation?
A parameter.
In JASP's descriptive plots, what option is used to identify specific data points that are outliers on a boxplot?
The 'Label Outliers' option.
A _____ plot is a graphical check for normality available in JASP's 'Descriptives' analysis.
Q-Q
What is a potential issue with tests of normality, like Shapiro-Wilk, when used with very large datasets?
They may become significant, indicating non-normality, even when the distribution looks fairly normal.
In JASP, what is the function of the plus sign (+) at the end of the data columns?
It opens a dialogue window to create a new or transformed variable.
What does 'effect size' measure in a statistical analysis?
It is a standard measure that describes the magnitude of the difference or the strength of a relationship, independent of sample size.
For a 2x2 contingency table, what two effect size measures are commonly used to analyze the categorical relationship?
Phi and the odds ratio.
What is the primary purpose of a one-sample t-test?
To determine if a sample mean is statistically different from a known or hypothesized population mean.
The _____ test is a non-parametric equivalent of the one-sample t-test used for dichotomous categorical data.
Binomial
What statistical test is an extended version of the Binomial test, used for categorical data with more than two categories?
The Multinomial test.
The Chi-Square 'Goodness-of-Fit' test compares observed categorical frequencies to what?
Expected frequencies based on a specific hypothesis (e.g., equal distribution or a known ratio).
What is the purpose of an independent samples t-test (Student's t-test)?
To determine if there is a statistical difference between the means of two independent groups.
What assumption about the variances of the dependent variable does an independent t-test make?
It assumes homogeneity of variance, meaning the variances should be equal in each group.
What test is used to check for homogeneity of variance in an independent t-test?
Levene's Test of Equality of Variances.
If Levene's test is significant, indicating unequal variances, what adjustment to the independent t-test should be used?
An adjusted t-statistic based on the Welch method.
What is the non-parametric equivalent of the independent samples t-test?
The Mann-Whitney U test.
The _____ t-test compares the means between two related groups on the same continuous, dependent variable.
paired samples
What is the null hypothesis ($H_0$) in a paired samples t-test?
The null hypothesis is that the pairwise difference between the two groups is zero.
What is the main assumption concerning the data for a paired samples t-test?
The differences between the matched pairs should be approximately normally distributed.
What non-parametric test is the equivalent of the paired samples t-test?
The Wilcoxon signed-rank test.
What does Pearson's correlation coefficient (r) measure?
It measures the strength and direction of the linear association between two continuous or ordinal variables.
What is the range of possible values for Pearson's correlation coefficient (r)?
The range is from -1.0 (perfect negative correlation) to +1.0 (perfect positive correlation).
What is the primary purpose of linear regression analysis?
To predict a dependent outcome variable from one or more independent predictor variables.
In the linear regression formula $y = c + b*x + \epsilon$, what does the 'b' term represent?
The 'b' term is the regression coefficient, representing the slope of the line.
In regression analysis, what are 'residuals'?
Residuals are the vertical differences between the actual data points and the predicted regression line.
What does the $R^2$ value in a regression analysis represent?
It represents the proportion of the variance in the dependent variable that is predictable from the independent variable(s).
What is the purpose of the Durbin-Watson statistic in regression output?
It checks for correlations between residuals, which can invalidate the test; values should ideally be around 2.
In multiple regression, what is the 'Forced entry' (or 'Enter') method of data entry?
It is the default method where all predictors are forced into the model in the order they are specified.
The _____ data entry method in multiple regression starts with all predictors and sequentially removes the least significant ones.
Backward
What do the VIF (Variance Inflation Factor) and Tolerance statistics check for in multiple regression?
They check for multicollinearity, which is when predictor variables are too strongly correlated with each other.
A one-way independent ANOVA is used to compare the means of how many groups?
Three or more independent groups.
One of the key assumptions of a one-way independent ANOVA is _____, which means the variance between groups should be similar.
homogeneity of variance
What is the purpose of post hoc testing after a significant ANOVA result?
To determine which specific group means are significantly different from each other.
When should post hoc tests, such as Tukey's, be carried out in an ANOVA?
Only if the overall ANOVA F-test is significant.
What is the non-parametric equivalent of the one-way independent ANOVA?
The Kruskal-Wallis test.
What does RMANOVA stand for?
Repeated Measures Analysis of Variance.
What does the assumption of 'sphericity' in a repeated measures ANOVA relate to?
It relates to the equality of the variances of the differences between levels of the repeated measures factor.
If the assumption of sphericity is violated in an RMANOVA, what correction should be applied to the ANOVA result?
The Greenhouse-Geisser correction (or Huynh-Feldt if epsilon is > 0.75).
What is the non-parametric equivalent of the repeated measures ANOVA?
The Friedman's test.
What is the primary purpose of an Analysis of Covariance (ANCOVA)?
To compare the means of independent groups while statistically controlling for the effects of a continuous variable (the covariate).
In ANCOVA, what does the 'homogeneity of regression slopes' assumption test?
It tests whether the relationship between the covariate and the dependent variable is the same across all groups.
What is a two-way independent ANOVA used to analyze?
It is used to examine the effect of two independent categorical variables (factors) on a continuous dependent variable.
In a two-way ANOVA, what is a 'main effect'?
A main effect is the effect of one independent variable on the dependent variable, ignoring the effects of other independent variables.
In a two-way ANOVA, a(n) _____ occurs when the effect of one independent variable depends on the level of another independent variable.
interaction effect
A _____ ANOVA is used when one factor is a between-subjects variable and another factor is a within-subjects (repeated measures) variable.
mixed factor
According to Navarro et al., the book 'Learning Statistics with JASP' is typically taught to what student population?
Undergraduate psychology students.
What is the 'belief bias' effect in logical reasoning?
It is the tendency to be influenced by the believability of a conclusion, rather than the logical validity of the argument.
What phenomenon occurs when a trend appears in several different groups of data but disappears or reverses when these groups are combined?
Simpson's paradox.
_____ is the process by which a vague concept is turned into a precise measurement.
Operationalisation
What scale of measurement involves categories with no intrinsic order, such as eye color?
Nominal scale.
What scale of measurement has a natural order but the intervals between the values are not necessarily equal, like finishing position in a race?
Ordinal scale.
What scale of measurement has meaningful differences between values but no true zero, such as temperature in Celsius?
Interval scale.
What scale of measurement has meaningful differences and a true zero, allowing for multiplication and division, such as response time?
Ratio scale.
A variable that can take on any value within a given range is called a _____ variable.
continuous
The reliability of a measure tells you how _____ you are measuring something.
precisely
The _____ of a measure tells you how accurate the measure is, or whether you're measuring what you intend to measure.
validity
In research, a _____ is an unmeasured variable that is related to both the predictor and the outcome, threatening internal validity.
confounder
A result that only holds in the specific situation tested in a study is called an _____, which threatens external validity.
artefact
What type of validity refers to the extent to which you can draw correct conclusions about the causal relationships between variables?
Internal validity.
What type of validity relates to the generalisability of research findings to 'real life' situations?
External validity.
_____ validity is the question of whether you’re measuring what you want to be measuring.
Construct
What is the defining characteristic of a 'Data Variable' in JASP?
It contains data loaded from an external file, such as a .csv file.
In JASP, variables that take their value by performing a computation on other variables are called _____.
Computed Variables
What does the median of a set of observations represent?
It represents the middle value when the observations are sorted in ascending order.
What measure of central tendency is most affected by skewed data and extreme outliers?
The mean.
The interquartile range (IQR) measures the spread of the _____ of the data.
middle half (or middle 50%)
What is the relationship between variance and standard deviation?
The standard deviation is the square root of the variance.
Why does JASP calculate sample variance by dividing by $N-1$ instead of $N$?
Dividing by $N-1$ provides an unbiased estimate of the population variance.
What is a z-score (or standard score)?
It is a value that indicates how many standard deviations an observation is from the mean of the distribution.
The law of large numbers states that as we collect more data, our sample statistics will tend to get closer to the true _____.
population parameters
What is a 'sampling distribution'?
It is the probability distribution of a given statistic (like the mean) based on a random sample of a certain size from a population.
The standard deviation of a sampling distribution is referred to as the _____.
standard error
What is the central limit theorem?
It states that for a large enough sample size (N), the sampling distribution of the mean will be approximately normal, regardless of the population's distribution.
An estimator is said to be _____ if, on average, it gives you the right answer (i.e., it equals the population parameter).
unbiased
What is a 95% confidence interval?
It is a range of values that we are 95% confident contains the true population parameter.
In hypothesis testing, what is the 'null hypothesis' ($H_0$)?
It is a statement of no effect or no difference, which a researcher aims to disprove.
What is a Type I error in hypothesis testing?
A Type I error is rejecting a true null hypothesis (a false positive).
What is a Type II error in hypothesis testing?
A Type II error is failing to reject a false null hypothesis (a false negative).
The probability of making a Type I error is denoted by the Greek letter _____.
alpha ($\alpha$)
The probability of making a Type II error is denoted by the Greek letter _____.
beta ($\beta$)
What is the 'power' of a statistical test?
Power is the probability of correctly rejecting a false null hypothesis, calculated as $1 - \beta$.
What is the 'critical region' (or rejection region) of a test?
It corresponds to the values of the test statistic that would lead to the rejection of the null hypothesis.
What does a p-value represent in frequentist statistics?
It represents the probability of obtaining test results at least as extreme as the results actually observed, under the assumption that the null hypothesis is correct.
A common mistake is to interpret the p-value as the probability that the _____ is true.
null hypothesis
What is the 'continuity correction' (or Yates correction) used for in a chi-square test?
It is an adjustment made when the test has only 1 degree of freedom to account for the approximation of a discrete distribution with a continuous one.
What are the key assumptions of chi-square tests?
Expected frequencies are sufficiently large (no cell < 1, and <20% of cells < 5), and the data are independent.
In a one-sample t-test, the t-statistic is calculated as the sample mean minus the hypothesized mean, divided by the _____.
standard error of the mean
What are the assumptions of the one-sample t-test?
Normality of the population distribution and independence of observations.
What is the key difference in assumptions between the Student's t-test and the Welch's t-test for independent samples?
Student's test assumes equal population variances, while Welch's test does not.
What is the general interpretation of Cohen's d?
It describes the difference between two means in terms of the number of standard deviations.
The _____ test is a formal statistical test for normality.
Shapiro-Wilk
In the _____ test, you rank all the data from both groups together and then calculate a statistic based on the sum of ranks in one of the groups.
Mann-Whitney U
What does Spearman's rank correlation measure?
It measures the strength and direction of the monotonic relationship between two ranked variables.
In multiple linear regression, what does the standardized coefficient (beta) represent?
It represents the change in the dependent variable (in standard deviations) for a one standard deviation increase in the predictor variable, holding other predictors constant.
The F-test in an ANOVA or regression analysis tests the null hypothesis that the overall _____ is not a significantly better fit to the data than a null model with no predictors.
model
The assumption of _____ in regression means that the variance of the residuals is the same for all values of the predicted outcome.
homogeneity of variance (or homoscedasticity)
In the context of regression diagnostics, what is an 'outlier'?
An outlier is an observation with a very large residual, meaning it is very different from what the regression model predicts.
In regression, an observation with high _____ is one that is very different from other observations in terms of its predictor variable values.
leverage
What is the fundamental logic of ANOVA?
It compares the variation between groups (SS between) to the variation within groups (SS within).
The test statistic in an ANOVA is the _____.
F-ratio (or F-statistic)
In a factorial ANOVA, what is a balanced design?
A balanced design is one where there are an equal number of observations in each group or cell.
In an unbalanced ANOVA, what is the main problem with Type I sum of squares?
The results of the hypothesis tests depend on the order in which the factors are entered into the model.
Which type of sum of squares is generally recommended for unbalanced ANOVA because it adheres to the principle of marginality?
Type II sum of squares.
In Bayesian statistics, what is the 'prior probability'?
It is the initial degree of belief in a hypothesis before observing the data.
In Bayesian statistics, the _____ represents the probability of observing the data given a particular hypothesis is true.
likelihood
Bayes' rule is used to update prior beliefs with data to produce a _____.
posterior probability
What does the 'Bayes Factor' (BF) quantify?
It quantifies the strength of evidence provided by the data for one hypothesis relative to another.
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