Rind, B., & Strohmetz, D. (1999). Effect on restaurant tipping of a helpful message written on the back of customers’ checks. Journal of Applied Psychology, 29, 139-144. doi:10.1111/j.15591816.1999.tb01378.x This is the article to use to answer these questions 1. What are the design elements (IV, DV) and operational definitions? 2. What are the potential confounds? 3. What are the strengths and weaknesses of the study design? 4. The message written on the back of the check concerned an upcoming special dinner at the restaurant. Is it possible that it was the content of the message rather than simply a personalized message from the server that accounts for the results? How might the authors have evaluated this possibility? 5. Researchers used index cards to randomly assign the dining parties to the experimental and control conditions. What other strategies could they have used for random assignment in this field experiment? 6. Why did the researchers instruct the server to behave in the same way when delivering the check at the end of the meal? What possible threats to internal validity might be created if the server’s behavior varied when delivering the check? 7. How might the following aspects of this study limit the study’s external validity? A young female adult was the authors’ accomplice. The study was conducted at a private country club. The meal was buffet style.
To answer these questions, let's analyze the research article by Rind and Strohmetz (1999) step by step:
1. The design elements (IV, DV) and operational definitions:
- Independent Variable (IV): The message written on the back of the check (experimental condition) vs. no message written on the back of the check (control condition).
- Dependent Variable (DV): Restaurant tipping.
The operational definitions are not explicitly mentioned in the question, but we can assume that the operational definition of tipping refers to the amount of gratuity left by the customers.
2. Potential confounds:
Potential confounds are variables other than the independent variable that could influence the dependent variable and lead to alternative explanations for the results. Without detailed information about the experiment, it is difficult to identify specific potential confounds in this study. However, some common potential confounds in the context of restaurant tipping could be factors like server's behavior, food quality, restaurant ambiance, or customer demographics.
3. Strengths and weaknesses of the study design:
The question does not provide much information about the study design itself. However, generally speaking, some potential strengths of this study design could include the use of a real-world setting (restaurant) and the manipulation of a specific condition (message on the back of the check) to test its effect on tipping behaviors. Weaknesses could include not controlling for all potential confounding variables and lack of random allocation of participants.
4. Evaluation of the message content:
To evaluate whether the content of the message or the personalized message itself influenced the results, the authors could have included a third experimental condition that had a message unrelated to the upcoming special dinner. This would help compare if the effect is due to the personalized message or the specific content of the message.
5. Alternative random assignment strategies:
In addition to using index cards, other random assignment strategies that could have been used in this field experiment include computer-generated random assignment, using a random number table, or assigning participants based on the order of their arrival.
6. Consistent server behavior:
The researchers instructed the server to behave in the same way when delivering the check to maintain consistency across participants. If the server's behavior varied, it could introduce a potential threat to internal validity because differing behaviors may influence customers' tipping behaviors independently of the experimental condition.
7. Limitations to external validity:
The aspects mentioned in the question - having a young female adult as the accomplice, conducting the study at a private country club, and serving a buffet-style meal - might limit the generalizability or external validity of the study. These aspects may not represent the population as a whole and could introduce bias. For example, tipping behaviors in a private country club setting might differ from other types of restaurants, and buffet-style meals might have specific norms or expectations related to tipping that differ from other types of dining experiences.