Unit 07

Unit 7:
Sampling Populations
 Unit 7: Assignment #1 (due before 11:59 pm Central on MON JUL 8):

  1. To learn what we mean by sampling:
    1. Read an excerpt from Simply Psychology’s (2019) article, “Sampling.”
      • Make sure you understand the difference between a sample and a population.
      • Make sure you understand why researchers draw samples from populations.
    2. Read an excerpt from Cherry’s (2014) article, “Sampling in Psychology.”
      • Again, make sure you understand the difference between a sample and a population.
      • Make sure you understand that the “larger the sample is, the more likely it will accurately reflect what exists in the population.”
    3. Read the beginning of Poldrack’s (2020) Chapter 7 “Sampling.”
      • For now, you only need to read the Introduction paragraph through Section 7.1 “How do we sample?”
      • Make sure you understand that the “goal in sampling is to determine the value of a statistic for an entire population of interest, using just a small subset of the population.”
  2. Now, that you understand sampling, it’s time to understand sampling error.
    1. Read the rest of Poldrack’s (2020) Chapter 7 “Sampling.”
      • Make sure you understand that sampling error is a measure that indicates how much the sample differs from the population.
      • Make sure you understand that our goal is to reduce sampling error.
      • Make sure you understand that, usually, the larger our sample, the smaller our sampling error.
    2. From Poldrack’s (2020) Chapter 7 “Sampling,” learn the following:
      • the Standard Error of the Mean (which is usually abbreviated as SEM) is one measure of how closely our sample resembles our population;
      • “a larger sample size will yield a smaller SEM … Thus, if we wish to improve our sample statistics … then we should use larger samples”; and
      • the formula for computing the SEM of a sample is your estimated standard deviation divided by the square root of your sample’s size (N).
  3. In your chosen data management platform, learn how to compute a SEM.
    1. First, learn how to compute a square root using the formula =SQRT(cell)
      • SQRT is a function built into your data management platform (just like COUNTIF and COUNTIFS), and
      • (cell) is the cell that contains the number for which you want to compute its square root.
      • Practice by finding the square root of 4.000 by
        • entering 4.000 in one cell, for example, the A2 cell;
        • then, in the C2 cell, write the formula =SQRT(A2).
        • Your result should be 2.000 (remember we always use three decimals) and look like this.
    2. Second, remind yourself how to divide one cell by another cell.
      • Remember you type an equal sign, followed by the dividend, a slash mark, and the divisor.
      • For example, to divide cell B2 by cell C2, you write the formula =B2/C2
    3. Now, put the two steps together!
      • Remember: The formula for computing the SEM of a sample is your estimated standard deviation divided by the square root of your sample’s size (N).
      • Remember: Your sample’s size is the number of participants you measured or things you observed. For example, when you collected data from five adults back in Unit 3, your sample size was 5.
      • Therefore, to compute the SEM of a sample:
        • First, compute the square root of your sample’s N using the formula =SQRT(N).
        • For (N), you can either type into the formula the number for N, for example, =SQRT(4.000), or you can select (or type) into the formula the cell name that contains your sample’s N, for example =SQRT(A2)
        • Second, divide the cell that contains your sample’s STDEV by the cell in which you computed the square root of your sample’s N.
      • Your formula should look something like this, and your final result should look something like this. Your actual numbers might differ!
  4. Now that you know how to compute an SEM, compute the SEM of three different size samples:
    1. the SEM of your Height Data in your original “Five Data,” which should be in your YourLastName_PSY-210_Unit03_FiveData spreadsheet.
      • The N for these data is 5 (because you sampled 5 adults).
    2. the SEM of your Chat Group’s combined Height Data, which should be in YourLastName_PSY-210_Unit03_Combined_FiveData spreadsheet.
      • The N for these data is either 10 (if you are in a Chat Group of two students, including yourself) or 15 (if you are in a Chat Group of three students, including yourself).
    3. the SEM of your assigned Height Data, which should be in YourLastName_PSY-210_Unit03_HeightFrequency spreadsheet.
      • The N for these data is 50.
  5. Create a bar graph of the three Height Data SEMs that you have computed:
    1. the SEM of your original “Five Data” Height Data;
    2. the SEM of your Chat Group’s Combined Height Data; and
    3. the SEM of your assigned Height Data.
      • Your Height SEM bar graph might look something like this.
      • Take a partial screenshot (not a screenshot of your entire screen) of your Height SEM bar graph (not your entire screen) and save the screenshot with the filename YourLastName_PSY-210_Unit07_Height_SEM_BarGraph_Screenshot.xxx (where xxx is the file type, for example, .jpg, .png, .jpeg, and the like).
  6. Compute the SEM of three other differently sized samples:
    1. the SEM of your Age Data in your original “Five Data,” which should be in your YourLastName_PSY-210_Unit03_FiveData spreadsheet.
      • The N for these data is 5 (because you sampled 5 adults).
    2. the SEM of your Chat Group’s combined Age Data, which should be in YourLastName_PSY-210_Unit03_Combined_FiveData spreadsheet.
      • The N for these data is either 10 (if you are in a Chat Group of two students, including yourself) or 15 (if you are in a Chat Group of three students, including yourself)
    3. the SEM of your assigned Age Data, which should be in YourLastName_PSY-210_Unit03_AgeFrequency spreadsheet.
      • The N for these data is 50.
  7. Create a bar graph of the three Age Data SEMs:
    1. the SEM of your original “Five Data” Age Data;
    2. the SEM of your Chat Group’s combined Age Data; and
    3. the SEM of your assigned Age Data.
      • Your Age SEM bar graph might look something like this.
      • Take a partial screenshot (not a screenshot of your entire screen) of your Age SEM bar graph (not your entire screen) and save the screenshot with the filename YourLastName_PSY-210_Unit07_Age_SEM_BarGraph_Screenshot.xxx (where xxx is the file type, for example, .jpg, .png, .jpeg, and the like).
  8. Go to the Unit 7: Assignment #1 Discussion Board and make a new Discussion Board post in which you do the following:
    1. In the first sentence of your Discussion Board post, state your unique data set number (e.g., “My unique data set number is 001″).
    2. Embed the two screenshots, one of your Height_SEM_BarGraph and the other of your Age_SEM_BarGraph.
    3. In one or two sentences, comment on the relation between the three sample sizes and the three SEMs in your Height_SEM_BarGraph.
      • Did your Height SEM graph illustrate the principle that the smaller the sample size, the larger the SEM?
    4. In another sentence or two, comment on the relation between the three sample sizes and the three SEMs in your Age_SEM_BarGraph.
      • Did your Age SEM graph illustrate the principle that the smaller the sample size, the larger the SEM?

Unit 7: Assignment #2 (due before 11:59 pm Central on MON JUL 8):

  1. Because it’s the middle of the term, it’s time to check in with your attitudes and anxiety about statistics:
    1. To assess your anxiety about statistics, complete this mid-course Statistics Anxiety Self-Assessment.
    2. To assess your attitudes toward statistics, complete this mid-course Attitudes Toward Statistics Self-Assessment.
  2. Because it’s the middle of the term, it’s also time to complete and submit your Course Journal for Unit 1 through Unit 7!
    1. First, make a typical Unit entry in your Course Journal for Unit 7. You should now have seven entries in your Course Journal.
    2. Second, prepare your Course Journal for submission to the Unit 7: Assignment #2 Discussion Board. If your Course Journal medium is
      • a Tumblr, Pinterest board, Prezi, Slideshare, blog, or website, you must embed the link in your Discussion Board post as you learned in the Course How To so that your link will show up as actual text, rather than just a URL);
      • a video, series of videos, podcast, or series of podcasts, or an audio journal, you must upload your videos or podcasts to a video or podcast hosting site (e.g., YouTube, Vimeo, Soundcloud, Podbean) and then EITHER embed the video as you learned in the Course How To (remember to “Embed Small”) OR embed the link in your Discussion Board post as you learned in the Course How To.
      • a journal (that’s not posted on a blog, Tumblr, or other website), you must convert your document to a PDF and attach the PDF to your Discussion Board Post.
        • Because Canvas only allows one file to be attached per Discussion Board post, you must attach each PDF to a new Discussion Board post by making a reply post to yourself
        • No .doc, .docx, .pages, or other filetypes besides PDF will be graded.
      • a PPT or Keynote, you must convert your PPT or Keynote file to a PDF and attach the PDF to your Discussion Board Post.
        • No .ppt, .pptx, .key, or other filetypes besides PDF will be graded.
    3. Third, test the size of your file, using this handout. If the size of your file is too large to email to yourself, reduce the size of your file following the suggestions in this handout.
    4. Fourth, if you are attaching a file, name your file YourLastName_PSY-210_CourseJournal_1-7.xxx
  3. Go to the Unit 7: Assignment #2 Discussion Board and make a new post in which you do the following:
    1. First, state the following “I have completed the mid-course Statistics Anxiety and Attitudes Toward Statistics Self-Assessments.”
    2. Second, embed or attach your Course Journal for Unit 1 through Unit 7.

Unit 7: Assignment #3 (due before 11:59 pm Central on TUE JUL 9):

  1. Because it’s the middle of the term, it’s also a good time to turn what you’ve learned so far in this course into something you can share with others.
    1. First, write down the fourteen things you have learned in the course that you chose to discuss in your Course Journal entries for Unit 1 through Unit 7.
      • Remember that in your Course Journal you are required to list two specific things you have learned in each unit.
      • Therefore, these fourteen things that you have learned in the course should come from your Course Journal (with two things per unit).
    2. Second, from that list of fourteen things, choose five of those things that you think are the most important for other students or the general public to know.
    3. Third, decide which medium, of three following three choices — Image/Gif Meme, TikTok, Infographic — you will use to share your five things with others:
      • Image or Gif Memes: If you choose to create Image or Gif Memes, you must make five Image or Gif Memes, which will be one Image or Gif Meme for each of the five things you think other students or the general public should know.
        • View some popular non-statistics memes here.
        • If you don’t know what an image or video meme is, be sure to first read this short background article by Adobe (2023).
        • Some sites that allow you to make Image or Gif Memes for free include Make A Meme and Kapwing.
        • Each of your Image or Gif Memes must be an image or gif saved as a .jpg, .jpeg, png, .gif, or the like and embedded into a Discussion Board Post. Remember to embed and re-size each image using the procedures you learned from the Course How To.
        • For each of your Image or Gif Memes, you must write an Image Description. To review how to write an Image Description, read an excerpt from Chen’s (2020) article, “How to Write an Image Description.”
      • TikToks: If you choose to create TikToks, you must make five TikTok videos, which will be one TikTok video for each of the five things you think other students or the general public should know.
        • If you’re unfamiliar with TikTok, consult Flex Clip’s (2020) article, “Ultimate TikTok Guide – How to TikTok.”
        • Each of your TikTok videos must be embedded as a URL into a Discussion Board Post. Remember to embed each URL using the procedures you learned from the Course How To.
        • For each of your TikTok videos, you must write an Image Description. To review how to write an Image Description, read an excerpt from Chen’s (2020) article, “How to Write an Image Description.”
      • Infographics: If you choose to create Infographics, you must make five Infographics, which will be one Infographic for each of the five things you think other students or the general public should know.
        • Some sites that allow you to make Infographics for free are Canva and Piktochart.
        • Each of your Infographics must be saved as a .pdf with the filename YourLastName_PSY-210_Infographic_XX.pdf (where XX is the number of the Infographic, e.g., 01, 02).
        • Be sure to test the size of your PDFs, using this handout. If the size of your PDF is too large to email to yourself, reduce the size of your PDF by following the suggestions in this handout.
    4. Regardless of the medium you choose, your Image/Gif Memes, TikToks, or Infographics must “G-rated,” meaning they must not contain any profanity or suggestive material. They must also not include any political content or political themes.
  2. Go the Unit 7: Assignment #3 Discussion Board and make a new Discussion Board post in which you do the following:
    1. List the fourteen things you wrote about in your Course Journal entries for Units 1 through 7.
    2. Identify which five of the fourteen things you’ve chosen to use for your Image/Gif Memes, TikToks, or Infographics.
    3. Embed, link to, or attach each of your five Image/Gif Memes, TikToks, or Infographics.
      • If you’ve chosen to make five Image/Gif Memes, embed each image into your Discussion Board post. Remember to embed and re-size your images using the procedures you learned from the Course How To. Underneath each image or gif, post the Image Description for that image or gif.
      • If you’ve chosen to make five TikToks, embed a link to each of TikTok into your Discussion Board post. Remember to embed your links using the procedures you learned from the Course How To. Underneath each TikTok video, post the Image Description for that TikTok video.
      • If you’ve chosen to make five Infographics, because Canvas allows only one file to be attached per Discussion Board post, attach each additional PDF by making another reply post to yourself and attaching an additional PDF to that reply post to yourself.

Unit 7: Assignment #4 (due before 11:59 pm Central on TUE JUL 9):

  1. Because it’s the middle of the term, it’s also a good time to revisit things you’ve learned so far in the course (which is why traditional lecture-based courses usually have midterm exams around the middle of the term).
  2. Listed below are Assignments you previously completed. Choose one Assignment from the list below that you enjoyed doing before and re-do that Assignment, according to the Assignment’s original instructions AND the additional requirements specified below.
    1. Unit 1: Assignment #3 – Teach what statistical thinking is and how it differs from intuition and from anecdotal evidence to three other people, meaning people who you did not previously teach about this topic.
    2. Unit 2: Assignment #2 – Make a different teaching document than you made before, aimed at a different audience than you aimed at before, and using a different medium than you used before.
    3. Unit 3: Assignment #1 – Collect data from 5 different people than you collected data from before and learn to use a different data management platform than you learned to use before).
    4. Unit 4: Assignment #1 – Find one more “good graph” and one more “bad graph”; these graphs cannot be any graphs that other students in your Section previously found and posted or any graphs that have been assigned during the course.
    5. Unit 5: Assignment #4 – Teach what it means to flatten the curve to three other people, meaning people who you did not previously teach about this topic.
    6. Unit 6: Assignment #2 – Calculate the base-rate and empirical probability of a different set of ten items with four different categories then you used before.
  3. Go to the Unit 7: Assignment #4 Discussion Board and make a new Discussion Board post containing everything that was previously required for the Assignment you’ve now re-done.
    1. State at the beginning of your post the Unit number and Assignment number (e.g., Unit 1: Assignment #3) of the Assignment you chose to do again.
    2. Also, explain in just one or two sentences why you chose this Assignment to do again.

Unit 7: Assignment #5 (due before 11:59 pm Central on WED JUL 10):

  1. Meet online with your small Chat Group for a one-hour text-based Group Chat at the time and date that your Chat Group previously arranged. DO NOT begin working on any of the steps listed below until your Chat Group begins their one-hour Group Chat.
  2. DURING YOUR ONE-HOUR GROUP CHAT:

    1. First, think back to the excerpt from Simply Psychology’s (2019) article, “Sampling.”
      • When this article was discussing drawing a sample from a population, it provided this diagram.
      • The diagram represents a sample as a smaller circle within a population, which is represented as the larger circle.
      • This type of diagram is called a part-whole diagram.
    2. Second, as a group, look through this set of part-whole diagrams.
      • Ensure that all members of your Chat Group understand the relations portrayed in the set of part-whole diagrams.
      • Ask questions, whenever needed!
      • Notice that one of the part-whole diagrams is simple, like the Simply Psychology part-whole diagram; it contains only one smaller circle inside one larger circle.
      • Notice that the other part-whole diagrams are more complex; they contain more than one circle inside a larger circle.
    3. Third, as a group, envision and design a total of FOUR part-whole diagrams.
      • Two of the four part-whole diagrams should be simple part-whole diagrams that contain only one smaller circle inside a larger circle.
      • Two of the four part-whole diagrams should be more complex part-whole diagrams that contain at least two circles inside a larger circle.
      • The topics of these part-whole diagrams can be anything — statistical thinking or any topic! However, they need to be G-Rated and not political.
      • Be sure to work as a group; your collaboration should be reflected in your Chat Transcript.
      • Save a partial screenshot (not a screenshot of your entire screen) of each of the four part-whole diagrams your Chat Group created naming the screenshots YourChatGroup_PSY-210_PartWhole_Diagrams_YY.xxx, where YY is the diagram number, e.g., 01, 02, and so forth, and xxx is the file type, for example, .jpg, .png, .jpeg, and the like.
    4. Fourth, and moving on to a different type of diagram, spend a few minutes reading independently through LucidChart’s (no date) article, “What is a Venn diagram?”
      • After reading through the article, ensure that all members of your Chat Group understand the relations portrayed in Venn diagrams.
      • Ask questions, whenever needed!
      • Notice that one of the Venn diagrams is simple; it represents the intersection of only two concepts.
      • Notice that the other Venn diagrams are more complex; they represent the intersection of three concepts.
    5. Fifth, as a group, look through this set of Venn diagrams.
      • Again, ensure that all members of your Chat Group understand the relations portrayed in Venn diagrams.
      • Continue to ask questions, whenever needed!
    6. Sixth, as a group, envision and design a total of SIX Venn diagrams.
      • Three of the Venn diagrams should be simple Venn diagrams that represent the intersection of only two concepts.
      • Three of the Venn diagrams should be more complex Venn diagrams that represent the intersection of at least three concepts (can be more than three, but at least three).
      • The topics of these Venn diagrams can be anything — statistical thinking or any topic! However, they need to be G-Rated and not political.
      • Be sure to work as a group; your collaboration should be reflected in your Chat Transcript.
      • Save a screenshot of each of the six Venn diagrams (not your entire screen) your Chat Group created naming the screenshots YourChatGroup_PSY-210_Venn_Diagrams_YY.xxx, where YY is the diagram number, e.g., 01, 02, and so forth, and xxx is the file type, for example, .jpg, .png, .jpeg, and the like.
  3. AT THE END of your one-hour Group Chat:
    1. Nominate one member of your Chat Group (who participated in the Chat) to make a post on the Unit 7: Assignment #5 Discussion Board that summarizes your Group Chat in at least 200 words. This Chat Group member should not post their 200-word summary of your Group Chat until they have completed their Course Journal for the current Unit.
      • At the end of the 200-word summary, this member needs to write this sentence filling the blanks: “I have completed my Course Journal for the current Unit. It contains ___ words and the two things I learned during this Unit about which I journaled about are ___ and ___.”
    2. Nominate a member of your Chat Group (who participated in the Group Chat using the browser Chrome on their laptop, rather than on their mobile device) to save the Chat transcript, as described in the Course How To (under the topic, “How To Save and Attach a Chat Transcript”).
      • This member of the Chat Group needs to make a post on the Unit 7: Assignment #5 Discussion Board and attach the Chat transcript, saved as a PDF, to that Discussion Board post. This Chat Group member should not post the transcript of your Group Chat until they have completed their Course Journal for the current Unit.
        • In their Discussion Board post, this member needs to write this sentence filling the blanks: “I have completed my Course Journal for the current Unit. It contains ___ words and the two things I learned during this Unit about which I journaled about are ___ and ___.”
      • Remember to attach the Chat transcript by clicking on the word “Attach.” (Do not click on the sidebar menu “Files.”)
    3. Nominate a third member of your Chat Group (who also participated in the Chat) to make another post on the Unit 7: Assignment #5 Discussion Board that states the name of your Chat Group, the names of the Chat Group members who participated in the Chat, the date of your Chat, and the start and stop time of your Group Chat. This Chat Group member should not post the names, date, and times of your Group Chat until they have completed their Course Journal for the current Unit.
      • In their Discussion Board post, this member needs to write this sentence filling the blanks: “I have completed my Course Journal for the current Unit. It contains ___ words and the two things I learned during this Unit about which I journaled about are ___ and ___.”
      • This member also needs to embed in their Discussion Post (not attach) the four screenshots of your Chat Group’s part-whole diagrams and the six screenshots of your Chat Group’s Venn diagrams.
        • Remember to embed and re-size each screenshot using the procedures you learned from the Course How To.
    4. If only two students participated in the Chat, then one of those two students needs to do two of the above three tasks.
    5. Before ending the Group Chat, bid goodbye to each other. In the next Unit, you will be forming new Chat Groups!

Congratulations, you have finished Unit 7! Onward to Unit 8!