matched pair

(noun)

A data set of two groups consisting of two samples that are dependent.

Related Terms

Examples of matched pair in the following topics:

  • Comparing Matched or Paired Samples

    • In a hypothesis test for matched or paired samples, subjects are matched in pairs and differences are calculated.
    • When performing a hypothesis test comparing matched or paired samples, the following points hold true:
    • In a hypothesis test for matched or paired samples, subjects are matched in pairs and differences are calculated.
    • shows that the corresponding "before" and "after" values form matched pairs.
    • Construct a hypothesis test in which the data set is the set of differences between matched or paired samples.

  • Using Two Samples

    • The groups are classified either as independent or matched pairs.
    • Matched pairs consist of two samples that are dependent.
    • The parameter tested using matched pairs is the population mean (see ).
    • Tests of matched or paired samples (necessarily a test of the population mean)
    • Distinguish between independent and matched pairs in terms of hypothesis tests comparing two groups.

  • Introduction

    • The groups are classified either as independent or matched pairs.
    • Matched pairs consist of two samples that are dependent.
    • The parameter tested using matched pairs is the population mean.

  • t-Test for Two Samples: Paired

    • Paired-samples $t$-tests typically consist of a sample of matched pairs of similar units, or one group of units that has been tested twice.
    • Paired samples $t$-tests typically consist of a sample of matched pairs of similar units, or one group of units that has been tested twice (a "repeated measures" $t$-test).
    • Pairs become individual test units, and the sample has to be doubled to achieve the same number of degrees of freedom.
    • A paired-samples $t$-test based on a "matched-pairs sample" results from an unpaired sample that is subsequently used to form a paired sample, by using additional variables that were measured along with the variable of interest.
    • The matching is carried out by identifying pairs of values consisting of one observation from each of the two samples, where the pair is similar in terms of other measured variables.

  • Student Learning Outcomes

  • Summary of Types of Hypothesis Tests

  • Comparing Two Populations: Paired Difference Experiment

    • McNemar's test is applied to $2 \times 2$ contingency tables with matched pairs of subjects to determine whether the row and column marginal frequencies are equal.
    • It is applied to $2 \times 2$ contingency tables with a dichotomous trait, with matched pairs of subjects, to determine whether the row and column marginal frequencies are equal ("marginal homogeneity").

  • Matched or Paired Samples

    • Two measurements (samples) are drawn from the same pair of individuals or objects.
    • The matched pairs have differences that either come from a population that is normal or the number of differences is sufficiently large so the distribution of the sample mean of differences is approximately normal.
    • In a hypothesis test for matched or paired samples, subjects are matched in pairs and differences are calculated.
    • The "before" value is matched to an "after" value and the differences are calculated.
    • Corresponding "before" and "after" values form matched pairs.

  • Wilcoxon t-Test

    • The Wilcoxon signed-rank t-test is a non-parametric statistical hypothesis test used when comparing two related samples, matched samples, or repeated measurements on a single sample to assess whether their population mean ranks differ (i.e., it is a paired difference test).
    • It can be used as an alternative to the paired Student's $t$-test, $t$-test for matched pairs, or the $t$-test for dependent samples when the population cannot be assumed to be normally distributed.
    • Other names may include the "$t$-test for matched pairs" or the "$t$-test for dependent samples."
    • Let $N$ be the sample size, the number of pairs.
    • Rank the pairs, starting with the smallest as 1.

  • The DNA Double Helix

    • The nitrogenous bases are stacked in the interior in pairs, like the steps of a staircase; the pairs are bound to each other by hydrogen bonds.
    • The two strands of the helix run in opposite directions, so that the 5′ carbon end of one strand faces the 3′ carbon end of its matching strand.
    • Only certain types of base pairing are allowed.
    • This means Adenine pair with Thymine, and Guanine pairs with Cytosine.
    • Adenine forms hydrogen bonds (or base pairs) with thymine, and guanine base pairs with cytosine.