# What is a related sample?

Table of Contents

## What is a related sample?

Related samples/groups (i.e., dependent observations) The subjects in each sample, or group, are the same. This means that the subjects in the first group are also in the second group.

### What is a related samples test?

Related Samples t. Use when: 1 group of subjects is tested more than once (e.g., pre-test / post-test)…or. 2 groups of related (or matched) subjects are measured once (e.g., twins)

**What is a repeated-measures study design?**

Repeated measures design is a research design that involves multiple measures of the same variable taken on the same or matched subjects either under different conditions or over two or more time periods. For instance, repeated measurements are collected in a longitudinal study in which change over time is assessed.

**What is an example of repeated-measures?**

It’s called Repeated Measures because the same group of study participants is being measured over and over again. For example, you could be studying the glucose levels of the patients at 1 month, 6 months, and 1 year after receiving nutritional counseling.

## What is a related sample in statistics?

Paired samples (also called dependent samples) are samples in which natural or matched couplings occur. This generates a data set in which each data point in one sample is uniquely paired to a data point in the second sample.

### What is a related samples design?

Related samples designs are used when large individual differences are expected and considered to be “normal”. Why? Because individual differences can contribute to sampling error. So by using related samples designs, one can reduce sampling error and have a better chance of finding a difference if there really is one.

**What is the difference between repeated measures and independent measures?**

1. Independent measures / between-groups: Different participants are used in each condition of the independent variable. 2. Repeated measures /within-groups: The same participants take part in each condition of the independent variable.

**What is an example of a repeated measures ANOVA?**

For example, you could use a repeated measures ANOVA to understand whether there is a difference in cigarette consumption amongst heavy smokers after a hypnotherapy programme (e.g., with three time points: cigarette consumption immediately before, 1 month after, and 6 months after the hypnotherapy programme).

## What is the difference between repeated-measures and independent measures?

However, the disadvantage of independent measures design is that there is the potential for error due to individual differences between the groups of participants. A repeated measures design consists of testing the same individuals on two or more conditions.

### Why use ANOVA repeated-measures?

The benefits of repeated measures designs are that they reduce the error variance. This is because for these tests the within group variability is restricted to measuring differences between an individual’s responses between time points, not differences between individuals.

**What are two related samples?**

The Two-Related-Samples Tests procedure compares the distributions of two variables. Example. In general, do families receive the asking price when they sell their homes?

**How are related samples different from independent samples?**

If the values in one sample affect the values in the other sample, then the samples are dependent. If the values in one sample reveal no information about those of the other sample, then the samples are independent.

## What are the two ways to create related samples?

Two types of design for selecting related samples are: the repeated-measures and matched-pairs designs.

### What type of t-test is repeated-measures?

A repeated-measures t-test (also known by other names such as the ‘paired samples’ or ‘related’ t-test) is what you should use in situations when your design is within participants. In a within participants design, participants contribute data for the dependent variable in ALL of the experimental conditions.

**What is an independent measures study?**

Independent Measures: Independent measures design, also known as between-groups, is an experimental design where different participants are used in each condition of the independent variable. This means that each condition of the experiment includes a different group of participants.

**What is a related t-test?**

What is meant by “related groups”? A dependent t-test is an example of a “within-subjects” or “repeated-measures” statistical test. This indicates that the same participants are tested more than once. Thus, in the dependent t-test, “related groups” indicates that the same participants are present in both groups.

## What is dependent measures design?

A within-subjects design is also called a dependent groups or repeated measures design because researchers compare related measures from the same participants between different conditions. All longitudinal studies use within-subjects designs to assess changes within the same individuals over time.