# The Process of Statistical Analysis in Psychology

# Web Activities

Click on the following links. Please note these will open in a new window.

*Activity 1*

**Population and sampling**

Your text discussed the need to sample from a larger population, as it is generally not possible to obtain data from every person in the population. In this activity, you will think about how sampling methods can contribute to sampling error.

Go to a social media site like Youtube.com, buzzfeed.com, or reddit.com. Click on any link of interest to you. Read the story, view the picture, or watch the video (whatever applies) and think of a comment that you would hypothetically post about it. Then read the remaining comments. For each comment, write down if it is positive, negative, or neutral. Try to get at least 25 comments. Ask yourself the following questions:

- How many of each type of comment do you have?
- What type of comment is yours? Positive, negative, or neutral? Does it fit with the majority of comments given?
- As most social media sites do not actively solicit feedback from every user, do you think that those who comment are representative of the population of people who view the link you did? Why or why not?
- Recently, websites such as amazon.com and ebay.com have been soliciting feedback from every customer by sending out emails asking for feedback. Do you think this decreases sampling error? Why or why not?

*Activity 2:*

**Shapes of distributions**

In this activity, you will learn about shapes of distributions and how outliers influence the shape of the distribution. Negative skew has a distribution tail on the left; positive skew has a distribution tail to the right.

Go to this link https://pudding.cool/2017/05/song-repetition/.

The first part of the web page discusses how the data were created. Essentially, the number of different words in the whole song is counted, and the number of characters in each of those words is totaled. This total is compared to the number of characters in the original song.

Scroll down to the middle of the page where there is a colorful figure entitled “The Repetition of Pop Music.” Examine the graph.

- Is it fairly symmetrical?
- If you think there is skew, in which direction is the skew?

Scroll down to the next section immediately below. Hover over the graph so it includes the 20 outliers. Examine the graph.

- It is fairly symmetrical?
- If you think there is skew, in which direction is the skew?
- How did the outliers influence the skew of the distribution?

*Activity 3:*

**Types of data**

In this activity, you will practice identifying types of data.

A pie chart is the round chart with percentages of categories identified.

A bar chart shows bars with the height corresponding to the frequencies of the categories.

A histogram is for continuous (non-categorical data), and the height corresponds to the frequencies of each data point on that continuum.

Nominal data are categorical. Interval and ratio data are continuous. Ordinal data are usually categorical, but percentile ranks are an exception to this and are continuous.

Go to http://memebase.cheezburger.com/graphjam. Scroll down until you find two different charts to represent data.

For each chart, answer the following questions:

- What kind of chart is it?
- What kind of data are represented? Nominal, ordinal, interval, or ratio?
- Is the chart a correct way to present the data? Why or why not?