POTENTIAL QUIZ QUESTIONS

T/F Random is Predicatable

• False: Randomness implies a lack of predictability or pattern. While certain patterns can emerge with a large enough dataset, each individual random event cannot be accurately predicted.

T/F Null hypothesis is the same as dependent variable.

• False: The null hypothesis (H0) is a statement used in hypothesis testing that suggests no effect or no relationship exists between variables. A dependent variable is a variable whose value is affected by other variables, typically used as the outcome or response variable in an experiment or analysis.

What is degrees of freedom?

the number of values in a calculation that are free to vary while still adhering to certain constraints. In statistics, degrees of freedom are used to determine the critical values for various distributions, like the t-distribution and chi-square distribution, which in turn help in hypothesis testing.

What is effect size?

a quantitative measure of the strength or magnitude of a phenomenon, relationship, or difference in statistics. It provides a standardized way to understand how substantial an observed effect is, regardless of sample size, unlike p-values which focus on statistical significance.

What is null hypothesis or alternative hypothesis?

(H0) represents the default or baseline assumption that there is no effect or no relationship between variables. The alternative hypothesis (H1 or Ha) is the statement that there is an effect or a relationship, challenging the null hypothesis. Hypothesis testing involves gathering evidence to determine whether to reject the null hypothesis in favor of the alternative.

Standard error decreases with sample size (vs. stays the same or increases)

True. Standard error decreases with sample size.

T/F one way to quantify the relationship between two variables is covariance

True. One way to quantify the relationship between two variables is covariance.

What are the 3 major goals of statistics?

are description (describing data), decision (drawing conclusions about a population based on sample data), and prediction (using data to make predictions about future observations).

How important is the null hypothesis in statistics and how often is it used?

as it provides a baseline assumption to be tested against an alternative hypothesis. It is used frequently in statistical hypothesis testing to determine if there is a significant difference or relationship between variables.

T/F There is a close relationship between confidence intervals and hypothesis testing.

True. There is a close relationship between confidence intervals and hypothesis testing.

T/F Hypothesis testing is “a wrongheaded view about what constitutes scientific progress”

True: If this statement is true, it implies that hypothesis testing is considered a misguided approach to understanding scientific progress, perhaps due to over-reliance on p-values or other statistical limitations. This view criticizes hypothesis testing for potentially distorting scientific inquiry and results.

Null Hypothesis vs. Alternative hypothesis

The null hypothesis is the hypothesis that there is no significant difference or relationship between variables, while the alternative hypothesis is the hypothesis that there is a significant difference or relationship between variables.

What is the General Linear Model?

a statistical framework used to analyze relationships between one or more independent variables and a dependent variable.

What are the main criticisms of null hypothesis testing?

its reliance on arbitrary cutoff values (such as p < 0.05), misinterpretation of p-values, and failure to account for practical significance.

What is a p-value?

the probability of obtaining test results at least as extreme as the observed results, under the assumption that the null hypothesis is true.

Why is it advisable to use a two tail test over a one-tail?

when you want to test for the possibility of a relationship or difference in either direction.

What are the two components to determine standard error?

the sample standard deviation and the sample size.

T/F The T distribution is slightly broader than the normal distribution

True. The T distribution is slightly broader than the normal distribution.

T/F The p-value is the probability of the data given that the alternative hypothesis is true (False!)

False. The p-value is the probability of obtaining the observed data or more extreme data if the null hypothesis is true.

What is Type I error?

occurs when the null hypothesis is rejected when it is actually true.

What is Type II error?

occurs when the null hypothesis is not rejected when it is actually false.

What does NHST stand for?

Null Hypothesis Significance Testing.

What percentage error in a significant result?

depends on the significance level chosen (typically 5% or 1% in NHST).

Is Null hypothesis testing deeply flawed?

it is deeply flawed is subjective and debated among statisticians.

What are the steps of hypothesis testing?

The steps of hypothesis testing typically include: stating the hypotheses, selecting a significance level, collecting data, performing the statistical test, and interpreting the results.

What is the end goal of hypothesis testing?

to make inferences about a population based on sample data and determine whether the results are statistically significant.

What is the difference between Type I and II errors?

Type I error occurs when the null hypothesis is incorrectly rejected, while Type II error occurs when the null hypothesis is incorrectly not rejected.

What are confidence intervals?

ranges of values that are likely to contain the population parameter being estimated, with a specified level of confidence.

List the factors that affect power.

sample size, effect size, significance level, and variability in the data.

What are examples of nominal & categorical data, versus interval/ratio/continuous data.

Nominal and categorical data are categorical variables where the values represent categories or groups. Interval, ratio, or continuous data are numerical variables where the values represent ordered categories and have meaningful numerical distances between them.

What is the null hypothesis?

a statement that there is no significant difference or relationship between variables.

What is a Chi-Square test?

a statistical test used to determine whether there is a significant association between two categorical variables.

T/F If the correlation is positive it deviates in opposite direction.

False. If the correlation is positive, both variables tend to move in the same direction.

What does the odds ratio do?

measures the strength and direction of the association between two variables in a case-control study.

What’s the standard way to represent data for a categorical analysis?

is often through frequency tables or contingency tables.

What is the definition for degrees of freedom?

represent the number of independent values or quantities which can be assigned to a statistical distribution.

Is the NHST the backbone of psychological research?

widely used in psychological research, but its role as the backbone is debated, as some argue for more nuanced statistical approaches.

Describe the effect of outlier data points?

significantly affect statistical analyses by skewing results or inflating variability, potentially leading to erroneous conclusions.