Matched Pair Design: Definition & Examples

matched pair design

Matched pair design remains the best option to pair subjects as it solely works best on instances of one participants with the likelihood of two treatment scenarios with matching variables. Pairwise matching of different subjects provides an excellent room of study that often yields conclusive results when investigated. The pairing process involves grouping of conditions that match before being subdivided further into different classes. With this, the pairing remains productive as the outcome often provides the anticipated answers of the study.

The use of matched pair design is one way to pair subjects effectually. For instance, college students are given different assignments that require them to pair given elements and classify them further for better results. These are some of the techniques used to prepare students to solve emerging problems in their professions. This guide helps you to get insights about matched pair design benefits, including its definition, disadvantages, and practical examples.

Matched Pairs Design Definition

Matched pair design is an essential element of the randomized block design that divides into blocks and subdivides them further. These blocks consist of participants with less variability within and between blocks. Typically, matched pairs experimental design is used only when the pairing includes two treatment outcomes with the subjects being categorized into a pair based on variabilities.

The resulting two groups are further subdivided based on age, gender, score, or models. That is, each paired subject can again be randomly assigned to different subgroups. As the experiment is random, the consequential treatments are unsystematically assigned to the subjects. The matched pair design purpose is to ensure each block contains variables with matching elements and can be quickly subdivided further.

A good matched design pair example is of a hypothetical medical experiment whereby 1000 subjects receive whether a placebo or vaccine treatment. Here, subjects are grouped into two pairs of 500 participants each. Within the two groups, individuals can again be classified based on age and gender. This example of matched pair design experiment suggests that a larger group is divided into two blocks, which can be further divided into different classes. A summary of the matched pair design as below;                                     

Pair Treatment
Placebo Vaccine
1 1 1
2 1 1
499 1 1
500 1 1

Matched Pair Design Advantages and Disadvantages

Matched pair design comes with benefits of pairing two treatment conditions essential for a particular study. Besides, the experiment accompanies detriments that leads to disadvantageous situations.

Advantages of Matched Pair Design Experiment

Accounts for Lurking Variable

When you categorize groups into pairs, there are instances where some variables are missed leading to inconclusive outcomes. Such cases affect decision making essential for a given condition. Matched pair design eliminates these instances by controlling lurking values that contribute to indecisive results.

For example, a matched pair design diagram with 500 groups paired based on either gender or age can impact weight differences. When we further subdivide groups based on age, we eliminate the variable of weight loss that can lead to lurking variables. As such, any weight loss can be associated with diet or exercise instead of age and gender.

Prevents Order Effect

Order effects are outcome differences that emerge from the way the order of experimental materials is presented. With this, the results are affected and can become ambiguous and reliable. When utilizing matched pair design statistics, the order of preliminary presentation has limited impacts on the results as specific subjects receive individual treatment.

For example, when the weight loss of 500 pairs solely depends on the standard diet used for a month, some individuals may lose while others may gain or maintain their weight. Notably, there will be an order effect as the subject uses a particular meal before another. Matched pair design statistics benefits only focus on gender and age factors rather than weight differences.

Reusing of Outcomes Across Different Conditions

Tests recorded from a given study can be reused as the results obtained are accurate even during a repeat. Matched pair design centers upon coupling subjects that match; hence the results obtained represent a similar population that matches the group sampled. This is another significant benefit as the tests and materials used can be recycled once more.

Disadvantages of Matched Pairs Design Psychology


Finding subjects requires a researcher to take lots of time trying to find matches for a given study. Basically, searching for subjects that match specified variables, especially when searching for two or more variables is time-wasting. Matched pair design examples for such a scenario include finding 50 female pairs that match in age or specific physical features to participate in your study.

Difficulty Matching Subjects

As a researcher, the goal is to find the right fit for a given group before commencing the study. Finding and matching the right subject can be challenging, particularly when looking for a larger group with rare variables. The best way to conquer such a situation is through working with identical twins with similar characteristics as they much perfectly under one block. Yet, working with a larger group remains problematic.

Likelihood of Loss of Subjects

Matched pair design ap stats are effective when both subjects participate in the study. But when one drops out, the entire study becomes worthless as both variables are needed for the best results. For instance, if you are working with a matching group under a specific block and one pulls out, the anticipated result may become inconclusive, therefore making the study imperfect.

Homework Help in Matched Pair Design

For example, there are 100 subjects involved in a study. By use of matched pair design characteristics, subjects are paired into two blocks of 50 subjects. Each block consists of individuals with identical variables essential for the study. Further, specific blocks are grouped in terms of gender and age.

Matched Pair Design Diagram Representation

matched pairs experimental design

Matched Pair Analysis

Matched pair analysis, also referred to as a matched-pair t-test, is used to examine differences between two pairs, whether related or matched. As parametric tests, these tests, however, include several assumptions that include;

  • Dependent variables are continuous
  • Observations are independent
  • Dependent variables are approximately standard
  • There are no outliers in dependent variables

When the matched pair t-test statistic is calculated, the value obtained is paralleled to the n-1 degrees freedom tabulated value. If the calculated value is higher than the tabulated value, there exists no significant claim. Several matched pairs design online help students or individual researchers to utilize the design to pair subjects for better results.

The analysis allows the researcher to make various conclusions for the study centered upon the findings. With several conclusions, you may wonder which of these statements is true for a matched-pair design. However, most of these statements are written from the results recorded when treatments are administered on specific groups.

Matched Pairs Design Vs Completely Randomized Design

Matched pair design is a specialized experiment of the randomized block design used when the case involves two sole treatment conditions. On the other hand, a completely randomized design is the uncomplicated experimental design based on data analysis and expediency. Participants are assigned treatments randomly with two pairs provided separate treatments each and results recorded.

Matched Pair Design Vs Block Design

When pairing subjects, block design involves subdividing groups into blocks with the variability within blocks being less than the variability between them. Subsequently, subjects in each block are assigned a treatment that delivers precise effects of the treatment. Unlike matched pair design, block design subjects are grouped further based on gender to determine the effectiveness of the treatment of both male and female.

Bottom Line

The matched pair design guideline and example helps you to tackle related questions. Do more practice to become perfect in this statistics field. Get statistics homework help, if the question at hand is tough!