BailiffMinkPerson699Experiments and Threats to Internal validity An elementary school…Experiments and Threats to Internal validity
An elementary school is trialing a new program to improve numeracy skills. The program is called FunNumbers”They have hired a research consulting firm to test the effectiveness of the program. The researcher had kids in grades 12and 3 experience either FunNumbersor another noneducational program, called “Jumpy DoodleAfter giving kids 2 weeks of experience in their program, she tested their numeracy skills using a standard numeracy assessment called “Mathalculator There are eight variations of the study described below. For each one:
a) Draw a diagram of the study design Note: not a
graph of the results, but a diagram of the design .
b) State if the design is a posttest onlypretest -posttest, repeated measures , or one group pretest-posttest
c) Identify the most likely threat to internal validity (if there is one). Name the threat and explain how internal validity is threatened.
1. All parents provided informed consent. Using the roll of a die, students were assigned to the FunNumbers (Experimental) game or the (Control) game. During school hours research assistants introduced the selected game to each child. Then, for the next 2 weeks, during each morning’s play period, kids were required to play with their respective game for 10 minutes. At the end of this 2-week period, the Mathalculator was administered. The mean score for kids in the FunNumbers group was 22, and the score for the JumpyDoodle kids was 8, a statistically significant difference. The researchers concluded that FunNumbers improved kids numeracy skills .
2. Teachers complained that JumpyDoodle was too wild and caused the children to become aggressive, so the researchers changed the study and eliminated the JumpyDoodle group. At the beginning of the fall, the kids in grades 1, 2, and 3 were tested on the Mathalculator (the mean of the 70 kids in the study was 9.0). Then, during school hours, research assistants (RAS) introduced the EunNumbers! game to each child who had permission to participate. For the next 2 weeks, during each morning’s free period, kids were required to play with this game for 10 minutes. At the end of this 2-week period, the Mathalculator was administered again. The mean score of the 70 kids had risen to 18.0, a statistically significant gain. The researchers concluded that FunNumbers! improved kids’ numeracy skills.
3. All parents provided informed consent. The researcher decided to save some research funds by pretesting all kids on the Mathalculator and focusing only on the kids who needed numeracy intervention the most. Overall, the average numeracy score was 10.0. The researcher selected the 20 kids who scored the lowest (their average Mathalculator score was 2.2). For the next 2 weeks, these kids played FunNumbers! in their morning play period. The researchers gave these 20 kids the Mathalculator again, and this time, their score had jumped to 6.0. The researchers concluded that FunNumbers ! improves kidsnumeracy skills.Social SciencePsychology
