Solved: Use the method of Example 1 and the LU-decomposition to solve the system

Chapter 11. More on Experimentation Highlight = Key terms Highlight = Important concepts More confounds  Even in a between­subjects “true” experiment, confounds can slip in: o Design confounds: something that inherently varies along with the independent variable. o Placebo effect: participants in a neutral control group respond to the “treatment” because they expect it to work. o Observer bias: the researcher’s expectations influence their interpretation of the results.  Can occur with any observational measure. o Demand characteristics: something in the experiment allows participants to guess what the study is about and change their behavior accordingly.  How can you avoid observer bias and demand characteristics o Double­blind study: neither the participants nor the researchers know which condition the participants are in.  Participant is practically blind in psychology studies, but the researcher often isn’t.  Demand characteristics can still sneak in. Bad experiments  One group, pretest/posttest design: one group of participants complete the dependent variable, then experience a treatment, then complete the measure again.  6 major threats to internal validity in one groups, pretest/posttest designs: o Maturation threat: a change in the dependent measure that occurs