Ch. 10 Experimental Designs Subgroups: 1. Between subject design a. Subjects assigned to independent groups using randomization 2. Randomized block design a. Subjects classified according to attribute variable and then randomized to treatment groups 3. Within-subject design or repeated measures design a. one group of subjects is tested under all conditions and each subject acts as his own control b. considered series of trails each with a single subject 4. Single-factor or one-way design or multi-factorial a. Experimental designs can also be described according to the number of independent variables or factors 5.Pretest-posttest control group design 6. Mixed design a. Study incorporates two independent variables, one repeated across all subjects and the other randomized to independent groups Ch. 11 Quasi-experimental Will LACK random assignment OR comparison groups OR both Used as reasonable alternative to randomized trial design Subgroups: 1. One group pretest-posttest design a. One set of repeated measures taken before and after treatment on one group of subjects 2. Time series design a. Multiple measurements before and after treatment used to study community interventions and policy changes 3. Nonequivalent pretest-posttest control group a. Subjects are self-selected due to research situations in social, clinical, and behavioral sciences b. Subjects not assigned to groups randomly- one treatment group, one control group 4. Nonequivalent posttest-only control group design a. Includes any number of treatment levels, with or without control group b. Uses existing groups who have and have not received treatment Ch. 12 Single-Subject Designs Must have a collection of repeated measurements of a behavioral response over time Must have 2 testing periods or phases: baseline and intervention Subgroups: 1. Withdrawal design a. Includes a second baseline and maybe a second intervention 2. Multiple baseline designs 3. Alternating treatment design 4. Multiple treatment design