Scientific Measurement and Variance

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What is the primary purpose of the null hypothesis in a research study?

To measure the variance in the sample data

To provide a default position to be disproven through the study (correct)

To prove the existence of a real effect or relationship

To calculate the correlation between variables

What is the main difference between sample variance and population variance?

Sample variance is used to measure correlation, while population variance is used to measure dispersion

Sample variance is calculated for a subset of the population, while population variance is calculated for the entire population (correct)

Sample variance is used to measure dispersion, while population variance is used to measure correlation

Sample variance is calculated for the entire population, while population variance is calculated for a subset of the population

What is the role of variance in psychological research?

To calculate the mean of the dataset

To reject the null hypothesis

To understand how individual data points deviate from the central tendency (correct)

To measure the correlation between variables

What is the purpose of dividing the sample standard deviation by the square root of the sample size?

To estimate the standard error of the mean (D) Signup and view all the answers

What is the primary reason for calculating variance in a dataset?

To quantify the spread or dispersion of values within the dataset (D) Signup and view all the answers

What type of research is more concerned with the principles of behavior and mental processes?

Basic research (D) Signup and view all the answers

What is the relationship between rejecting the null hypothesis and the alternative hypothesis?

Rejecting the null hypothesis means there is sufficient evidence to conclude there is a real effect or relationship (A) Signup and view all the answers

What is the primary reason for using statistical methods in psychological research?

To bring up the idea of variance and quantify the spread or dispersion of values (A) Signup and view all the answers

What is the main advantage of within-subjects designs?

The ability to reduce sequencing effects (A) Signup and view all the answers

What is the purpose of using a factorial design in an experiment?

To examine the interaction between multiple independent variables (B) Signup and view all the answers

What is the main difference between experimental and correlational research?

Experimental research involves manipulating variables, while correlational research involves observing naturally occurring variables. (A) Signup and view all the answers

What is the purpose of using a statistical test to assess the fit of a model?

To determine the significance of the model's parameters (A) Signup and view all the answers

What is the primary reason why psychological research often deals with variance?

Because it is impossible to measure human behavior precisely (B) Signup and view all the answers

When should you calculate sample variance?

When your dataset represents a sample taken from a larger population of interest (A) Signup and view all the answers

What is the notation for the sum of the values in the sample?

Σ (B) Signup and view all the answers

What is the purpose of using the formula for estimating population variance?

To estimate the population variance from a sample (C) Signup and view all the answers

Why do we use the unbiased estimate of population variance (/n-1) instead of (/n)?

Because it produces a more accurate estimate of the population variance (B) Signup and view all the answers

What is the assumption made in the first estimator of population variance?

We know the population mean (B) Signup and view all the answers