Standard DA-2 Indicator 2 Standard DA-2 Indicator 2.1: Classify data collections as surveys, observational study, or experimental study Objective 1: TSWBAT review and add some more concepts to nature of statistics. Objective 2: Students will solve the problems in review exercises from 7-18 pages 26 and 27.
Types of statistics, population, sample, types of data, types of variables, levels of measurement, sampling techniques, types of study (observational, experimental), independent variable, dependent variable Keywords
Observational Study The researcher merely observes what is happening or what has happened in the past and tries to draw conclusions based on these observations. Example 1: A research study comparing the risk of developing lung cancer between smokers and non- smokers Example 2: A Study of Long-term Psychological Effects of the Death of a Close Relative
Experimental Study In an experiment investigators apply treatments to experimental units (people, animals, plots of land, cars, etc.) and then proceed to observe the effect of the treatments on the experimental units. Example: Find 100 women age 20 who do not currently smoke. Randomly assign 50 of the 100 women to the smoking treatment and the other 50 to the no smoking treatment. Those in the smoking group smoke a pack a day for 10 years while those in the control group remain smoke free for 10 years. Measure lung capacity for each of the 100 women. Analyze, interpret, and draw conclusions from data.
Independent/Dependent Variable The independent variable in an experimental study is the one that is being manipulated by the researcher. The resultant variable is called dependent variable. Example 1: You are doing a research in medical field about how stress affects heart rate in humans. Your independent variable would be the stress and the dependent variable would be the heart rate. Example 2: Intensive study program/GPA
Review Exercises problems 7-18 Write down the complete statement for which you’re describing the types of data in each problem.