## Standard deviation (SD)Is a measure of variability; it shows how much variation or dispersion a group of observation exhibit from the mean, or from an expected value. A low standard deviation indicates that the data points tend to be very close to the mean; high standard deviation indicates that the data points are spread out over a large range of values. It is the square root of the variance. |

## Standard error (SE)A measure of the precision of the sample mean of the different samples obtained to estimate the population. Its value decreases as the sample size increases, as the chance of variation from the population mean is reduced. It depends on both the standard deviation and the sample size (SE = SD/√(sample size). The SE can be calculated to other statistic measures (descriptors) than the mean. |

## Statistical hypothesisRefers to a statement on which hypothesis testing will be based. Particularly important statistical hypotheses include the null hypothesis and the alternative hypothesis. |

## Statistical testingA general term for the procedure of assessing whether sample data is consistent with the scientific hypothesis formulated. |

## Statistical testsStatistical procedures to determine whether there is enough evidence to "reject" or “accept” a statement or hypothesis. |

## StatisticsIs the study of the collection, organization, analysis, interpretation, and presentation of data. The term is also used to represent the numerical characteristics of a sample (ex: the sample mean, variance…). |

## StorylineDevelops the plot of the game as well as the characters and objects in the game and the settings that connect them into an emotional narrative that is gradually released as the game progresses. |

## Strategy GameA game that focuses on gameplay requiring careful and skillful thinking and planning in order to achieve victory. |

## Stratified samplingA variant on simple random and systematic sampling methods and is used when there is a number of distinct subgroups, within each it is required that there is full representation. A stratified sample is constructed by classifying the population in sub-populations (or strata), based on some well-known characteristics of the population, such as age, gender or socio-economic status. The selection of elements is then made separately from within each strata, usually by random or systematic sampling methods. |

## Student’s t-testSignificance test for assessing hypothesis about population means; a single sample t-test is used in situations where it is required to test whether the mean of a population takes a particular value; an independent samples t-test is designed to test the equality of the means of two populations, when independent samples are available from each population. |