Udacity Data Analyst December 2017 - May 2018.
Project 5: Test a Perceptual Phenomenon using Null Hypothesis
In a Stroop task, participants are presented with a list of words, with each word displayed in a color of ink. The participant’s task is to say out loud the color of the ink in which the word is printed. The task has two conditions: a congruent words condition, and an incongruent words condition. In the congruent words condition, the words being displayed are color words whose names match the colors in which they are printed: for example RED, BLUE. In the incongruent words condition, the words displayed are color words whose names do not match the colors in which they are printed: for example PURPLE, ORANGE. In each case, we measure the time it takes to name the ink colors in equally-sized lists. Each participant will go through and record a time from each condition.
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What is our independent variable? What is our dependent variable?
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What is an appropriate set of hypotheses for this task? Specify the null and alternative hypotheses based on what you think the researchers might be interested in. Justify your choices.
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Report some descriptive statistics regarding this dataset. Include at least one measure of central tendency and at least one measure of variability.
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Provide one or two visualizations that show the distribution of the sample data. Write one or two sentences noting what you observe about the plot or plots.
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Now, perform the statistical test and report your results. What is your confidence level or Type I error associated with your test? What is your conclusion regarding the hypotheses you set up? Did the results match up with your expectations? Hint: Think about what is being measured on each individual, and what statistic best captures how an individual reacts in each environment.