【优达学城测评】Project 1

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Q1：问题回复正确确认了试验中的自变量和因变量。

• Please note that an independent variable, sometimes called an experimental or predictor variable, is a variable that is being manipulated in an experiment in order to observe the effect on a dependent variable, sometimes called an outcome variable.
• We are taking control of the word color congruency condition and observe the time taken for each individual to name the ink color.

Q2a：零假设和对立假设均以文字和数学方式进行了明确说明。数学陈述中的符号也进行了定义。

Please consider to refer the mathematical symbols to the population means explicitly.

• A hypothesis test is a statistical test that is used to determine whether there is enough evidence in a sample of data to infer that a certain condition is true for the entire population.
• A hypothesis test examines two opposing hypotheses about a population: the null hypothesis and the alternative hypothesis. The null hypothesis is the statement being tested. Usually the null hypothesis is a statement of "no effect" or "no difference". The alternative hypothesis is the statement you want to be able to conclude is true.
• Please refer to the illustration below:
  

Q2b：通过统计检验来辩证提出的假设，并针对统计检验的假设前提进行说明

• Please look at here for a more detailed assumptions for conducting t-test.
• The t-test for dependent means is considered typically "robust" for violations of normal distribution.This means that the assumption can be violated without serious error being introduced into the test in most circumstance.
• However, if we are conducting a one-tailed test and the data are highly skewed, this will cause a lot of error to be introduced into our calculation of difference scores which will bias the results of the test. In this circumstance, a nonparametric test should be used.