# Glossary Hub 用語集ハブ

This glossary indexes frequently used research terms. Glossary entries come from different sources: imports, and manual entries by users. The first bulk of glossaries was imported directly from the book *Exploring educational research literacy*. Others are manually added by different users over time.

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q |

**R**| S | T | U | V | W | X | Y | Z | ALL

## R |
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## rCorrelations are a great tool for learning about how one thing changes with another. Correlation values closer to 0 are weaker correlations, while values closer to positive or negative 1 are stronger correlation. (Source)In statistics, the Pearson correlation coefficient (PCC) ― also known as Pearson's r, the Pearson product-moment correlation coefficient (PPMCC), the bivariate correlation, or colloquially simply as the correlation coefficient ― is a measure of linear correlation between two sets of data.It is the ratio between the covariance of two variables and the product of their standard deviations; thus, it is essentially a normalized measurement of the covariance, such that the result always has a value between −1 and 1 (-1 ≤ ). (Source) r ≤ 1The " r value" is a common way to indicate a correlation value. More specifically, it refers to the (sample) Pearson correlation, or Pearson's r. The "sample" note is to emphasize that you can only claim the correlation for the data you have, and you must be cautious in making larger claims beyond your data. (Source) | ||

## Random SampleAn important type of Sample in Quantitative Research. When a Sample is chosen at random, it lessens the chance for any sort of systematic distortion of that Sample in relation to the Population. | ||

## RangeThe most primitive measure of Dispersion; it is the distance between the lowest score and the highest score. | ||

## Raw DataData that have been collected but not yet analyzed. | ||

## ReferencesThe part of an article where the published sources that were actually cited in the article are listed alphabetically. | ||

## Regression | ||

## ReliabilityA Statistical test used to measure the accuracy of the process used to gather Data. Some common forms of Reliability include test-retest reliability, alternate forms reliability, and internal consistency. | ||

## Repeated MeasuresA Statistical Research Design used in Quantitative Research where Data is gathered from the same Participants at different times. A Pretest-Posttest design is a simple form of repeated measures. | ||

## ReplicationThe ability to repeat a research process and get the same answer. Most important in Quantitative Research. | ||

## Representative SampleA type of Sample where some effort has been made to make sure the Sample resembles the Population in one or more important ways. | ||