Random Sampling Playing cards are our participants Our population is all 52 cards in the deck Vary on three characteristics: Color red or black Suit hearts, diamonds, spades, or clubs Type number (2-10) or face (J, Q, K, and A) Make a list of at least five characteristics that human subjects might vary on.

Random Sampling

Random Sampling Shuffle deck thoroughly before each trial For the first trial, randomly sample 5 participants and count how many of each characteristic you have Next, calculate the percentage of each by dividing by 5 and then multiplying your answer by 100 Repeat for 10 participants and then again for 20

In a playing card population, there are: 50% black, 50% red 25% hearts, 25% diamonds, 25% spades, and 25% clubs 69% number, and 31% face Questions: 1) In which group (5, 10, or 20) were your percentages closest to the population totals above? What does this tell you about sample size in any experiment? 2) Why do researchers use random sampling instead of trying to select a representative sample themselves? 3) Explain the difference between random sampling and random assignment.