EDIT 6900: Research Methods in Instructional Technology UGA, Instructional Technology Spring, 2008 If you can hear audio, click If you cannot hear audio, click If you have a question, click Lloyd Rieber Instructor Eunjung Oh Graduate Assistant

Two Topics for Today Introduction to Quantitative Research Methods (just beginning) Overview of a class activity on how to compute the mean, standard deviation, and z scores.

Not This Week

Informal Activity SDC Systematic Data Collection An informal, (hopefully) enjoyable activity designed to give you first-hand experience collecting research data Your Task: Go and research something of interest to you! Report on it informally in writing Give 5 minute oral report 10%, Due: April 9

March 26Quantitative Research (con’t) April 2Quantitative Research April 9Preparing a Research Report SDC Reports (in class) April 16Finish SDC Reports (if needed) Research Project Presentations? April 23Research Project Presentations Remaining Course Calendar

Notes About the Next RDA

Course Project: Will you do this individually or with a partner? Date to decide by: February 5 To declare your intention, update your class profile and write the name of your partner or the word “individual” in the field titled “Project Team.”

Dr. Lloyd Rieber The University of Georgia Department of Educational Psychology & Instructional Technology Athens, Georgia USA EDIT 6900 Research in Instructional Technology Part IV. Quantitative Research Methodologies Chapters 9-11

Quick Polls on this Chapter

Descriptive Research  Examines situation as it is.  Does not involve changing or modifying situation under investigation.  Not used to determine cause-and-effect relationships.

Surveying a Population: the United States Census

Excerpts From Ruling on Planned Use of Statistical Sampling in 2000 Census Reading section 141(a) and section 195 together, and considering the plain text, legislative history and other tools of statutory construction, this court finds that the use of statistical sampling to determine the population for purposes of the apportionment of representatives in Congress among the states violates the Census Act....

Two Important Sets of Descriptive Statistics Measures of Central Tendency Measures of variability

The Normal Distribution Cool simulation of a classic phenomenon resulting in a normal curve –

Measures of Central Tendency Mean –The average of a set of numbers. Median –Given a set of number arranged in descending order, the median is the number at the midpoint. Mode –Given a set of numbers, the mode is the number with the greatest frequency. Given a normal distribution, these are all the same number.

How to measure variability? Method 1: Compute the difference between the highest and lowest score –OK, but this only takes into account 2 scores! Method 2: Method 3:

How to measure variability? Method 1: Compute the difference between the highest and lowest score –OK, but this only takes into account 2 scores! Method 2: Compute the difference between each score and group average –OK, these are called deviation scores. –Great! Let’s take the average of them. –Oops! The answer is always 0! Method 3

How to measure variability? Method 1: Compute the difference between the highest and lowest score –OK, but this only takes into account 2 scores! Method 2: Compute the difference between each score and group average –OK, these are called deviation scores. –Great! Let’s take the average of them. –Oops! The answer is always 0! Method 3: Compute the standard deviation –Pretty much still the average of these numbers, but you square the difference scores first, then take the square root. Pretty clever!

Standard Deviation

67 Years Since the Last.400 Hitter: Baseball and the Importance of Variance The major league batting average has always been around.260.

z Scores Your friend tells you he received a 95 on a recent math exam. Are you impressed?

Calculating z Scores  Using the mean and standard deviation to calculate z (standard) scores  A standard score shows how far an individual’s performance is from the mean in standard deviation units.

Class Activity Learning How to Compute the Mean, Standard Deviation, and z Scores of a Data Set

Did you say mathematics?

Your Task (This has already been ed to you.) 1.Finish watching my pre-recorded presentation introducing quantitative research methods first. 2.Launch Excel and create a spreadsheet. 3.Compute the mean, standard deviation, and z scores of the data set ed to you. Follow my video tutorial. 4. your spreadsheet to me as an attachment. (You do not have to finish this evening, but I expect most will.)

This is meant as a class activity. It is not a graded activity. If you get stuck and become totally frustrated, stop and send me what you have.

To do list Follow the Course Learning Plan!