Research Strategies SurveysObservationsExperiments And other stuff…
Research Strategies Fall Into 2 Categories Descriptive - strategies for observing and describing behavior Observation Observation Surveys Surveys Experiments - strategies for inferring cause and effect relationships among variables
Longitudinal and Cross-Sectional Studies
Longitudinal Study Researchers study the same group of individuals for many years to see how they change. Drawbacks: Expensive & difficult to conduct Risky – people may drop out
Cross-Sectional Study Researchers study a number of subjects from different age groups and then compare the results to see how they’re different. Cheaper & easier
Laboratory Observation The environment can be controlled to minimize the number of variables. Negatives = it may cause the subject to act differently than it normally would. Ex: Skinner Box, maze, fish tank
Naturalistic Observation Subjects are observed in their “natural” environment Not aware they are being watched – researcher does not interfere Could use hidden cameras or two way mirrors Ex: Watching students in your classes.
Case Study In depth study of one individual Used to investigate rare, unusual, or extreme conditions Example: Phineas Gage Example: Phineas GageNegatives: Open to bias Difficulty of applying data from one person to everyone
Survey Method Relies on self-reports; uses surveys, questionnaires, interviews. Efficient and inexpensive method Can you guess some limitations of this method of research?
Survey Limitations Accuracy = people are not always honest. People fear confidentiality Example: Tooth brushing survey in 1960s. If as many people actually brushed their teeth as often as they claimed to brush their teeth, 33% (?) more toothpaste would have been sold that year.
Random Sample Sample which represents the target population: Each member of the population has an equal chance of being included. Each member of the population has an equal chance of being included. If not random then it’s biased. If not random then it’s biased. How would you pick a random sample??? How would you pick a random sample???
Unfairness = Bias = incorrect conclusions. Volunteers have things in common. Peeps who don’t volunteer do too. Those who complete a survey are often willing to share. Participants act differently because they know they’re being observed. Bias
Why would these samples contain bias? 5 million motorcycle owners to represent American population Randomly selecting people from a phone book Surveying people who subscribe to a magazine
Eliminating Bias Single Blind Study – Participants do not know if they are receiving the treatment or the placebo Double Blind Study – Neither the participants nor the researchers know if they are administering the treatment or the placebo.
Correlational Study Examine the relationship of how closely one thing is related to another Collects a set of facts Correlation reveals relationships among facts The higher the crime the lower the SAT scores. The higher the crime the lower the SAT scores. Correlation studies are helpful in making predictions. Correlation CANNOT prove causation Does NOT determine why the two variables are related--just that they are related.
Examples Do democratic parents produce better behaved children? Do democratic parents produce better behaved children? Do better behaved children encourage parents to be democratic? Do better behaved children encourage parents to be democratic?
Correlation Positive The more days you work the more money you bring home each month. The more days you work the more money you bring home each month.Negative The more days you’re absent from school the lower your grades are for a class. The more days you’re absent from school the lower your grades are for a class.Zero Does shoe size = intelligence? Does shoe size = intelligence?