The External Validity of Experiments

This study examined the effects of strategic, motivational self-talk for runners completing a 60-mile, overnight ultramarathon using a randomised, controlled experiment. Data were collected before, during, and after an annual ultramarathon. Twenty-nine ultramarathon runners were randomly allocated to a motivational self-talk group or an alternative control group. A condition-by-time mixed ANOVA indicated that learning to use motivational selftalk did not affect pre-event self-efficacy or perceived control. A t-test and magnitude-based inference indicated that motivational self-talk did not affect performance. Nevertheless, followup data suggested that most participants found the intervention helpful and continued to use it six months after their research commitment, particularly in endurance events and to a lesser extent in training. Participants continued to use self-talk to cope with exertion, as well as other stressors such as blister discomfort and adverse conditions. Suggestions are offered for future research examining the effects of psychological interventions on performance in endurance events. "Effects of a Motivational Self-Talk Intervention for Endurance Athletes Completing an Ultramarathon" by McCormick A, Meijen C, Marcora S The Sport Psychologist © 2017 Human Kinetics, Inc.Psychological skills training (PST) can enhance endurance performance. Although selftalk, imagery, goal setting, and packages including multiple PST strategies consistently enhance endurance performance in non-competitive laboratory and field-based endurance tasks, few studies have examined the effects of psychological interventions such as PST on performance in actual endurance events, and these studies showed equivocal intervention

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“…Bracht & Glass, 1968). The participants included in the study may not therefore be representative of ultramarathon runners as a population.…”

Section: Limitationsmentioning

confidence: 99%

Effects of a Motivational Self-Talk Intervention for Endurance Athletes Completing an Ultramarathon

McCormick

Meijen

Marcora

2018

The Sport Psychologist

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“…Where analysis of variance is employed then mean outcome scores will be examined at blocked high and low levels of aptitude. A significant F-ratio for interaction, with crossing graphs of cell means, was formerly considered suffcient for disordinality (Lindquist, 1953 ;Lubin, 1961), but Bracht (Bracht and Glass, 1968) proposed more stringent criteria, conservative in relation to the risk of false rejection of the ordinality hypothesis. Differences between outcome means at both high and low levels of the aptitude variable were required to be separately significant, as well as opposite in sign.…”

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confidence: 99%

Decision Rules for Teaching Strategies in Primary Schools: Personality‐treatment Interactions

Trown

Leith²

1975

Brit J of Edu Psychol

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SUMMARY.A mathematical task was used among 432 junior school pupils in a search for personality-teaching strategy interactions. Factors of sex, ability, anxiety, extraversion, model and teaching strategy were incorporated into a replicated design. An inductive, learnercentred exploratory strategy and a deductive teachercentred supportive strategy each employed the same mathematical models. There was no evidence of strategy-ability or strategy-extraversion interactions but the strategy-anxiety interaction was significant. Linear functions, relating the retained learning outcome to anxiety score, were used as the basis of decision rules for differential instruction. Pupils at the lower end of the anxiety range may be assigned to the exploratory strategy and those at the upper end of the range to the supportive strategy if advantage is taken of the disordinal nature of the observed interaction. The consistency of a negative linear relationship between outcome and anxiety for the exploratory strategy contrasted with the complex pattern associated with the supportive strategy. In the latter case, linear functions of differing sign afforded predictability for subgroups of introverts and extraverts and for subgroups of low ability and high ability children. When all data were combined for the supportive strategy, however, a non-linear relationship was revealed.INTRODUCTION IF a line of regression relating learner-aptitude to learning outcome is drawn for each treatment under consideration, then non-parallelism w i l l indicate the presence of an aptitude-treatment interaction (ATI). An ordinal interaction is defined as one in which the order of treatments A and B is the same over the entire aptitude range, i.e., one treatment is superior overall (Figure 1). Where the regression line for treatment A crosses the regression line for treatment B within the aptitude range, however, the interaction is said to be disordinal and decision rules for differential instruction may be formulated. Pupils at one end of the aptitude range may be assigned with advantage to one treatment, while those at the other end of the range are assigned to the alternative treatment.Where analysis of variance is employed then mean outcome scores will be examined at blocked high and low levels of aptitude. A significant F-ratio for interaction, with crossing graphs of cell means, was formerly considered suffcient for disordinality (Lindquist, 1953 ; Lubin, 1961), but Bracht (Bracht andGlass, 1968) proposed more stringent criteria, conservative in relation to the risk of false rejection of the ordinality hypothesis. Differences between outcome means at both high and low levels of the aptitude variable were required to be separately significant, as well as opposite in sign. Reaction against the severity of this suggestion (Leith, 1972 ;Cronbach and Snow, 1973) has been based upon the extremely low probability of joint occurrence of two separately significant events. A recent distinction has been made between research set up Dr. Trown is now in the Depa...

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“…In addition, in this section, we address some threats to the external validity of our experimental study. External validity refers to which extent our results and findings are applicable to other groups of populations [25]. In our study, we reported a possible threat to external validity that can be encountered, which is the interaction effect of the selection of our sample.…”

Section: Discussionmentioning

confidence: 75%

Employing Behavioral Analysis to Predict User Attitude towards Unwanted Content in Online Social Network Services: The Case of Makkah Region in Saudi Arabia

Alsulami

Al-Aama

2020

Computers

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The high volume of user-generated content caused by the popular use of online social network services exposes users to different kinds of content that can be harmful or unwanted. Solutions to protect user privacy from such unwanted content cannot be generalized due to different perceptions of what is considered as unwanted for each individual. Thus, there is a substantial need to design a personalized privacy protection mechanism that takes into consideration differences in users’ privacy requirements. To achieve personalization, a user attitude about certain content must be acknowledged by the automated protection system. In this paper, we investigate the relationship between user attitude and user behavior among users from the Makkah region in Saudi Arabia to determine the applicability of considering users’ behaviors, as indicators of their attitudes towards unwanted content. We propose a semi-explicit attitude measure to infer user attitude from user-selected examples. Results revealed that semi-explicit attitude is a more reliable attitude measure to represent users’ actual attitudes than self-reported preferences for our sample. In addition, results show a statistically significant relationship between a user’s commenting behavior and the user’s semi-explicit attitude within our sample. Thus, commenting behavior is an effective indicator of the user’s semi-explicit attitude towards unwanted content for a user from the Makkah region in Saudi Arabia. We believe that our findings can have positive implications for designing an effective automated personalized privacy protection mechanism by reproducing the study considering other populations.

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The External Validity of Experiments

Cited by 419 publications

References 56 publications

Effects of a Motivational Self-Talk Intervention for Endurance Athletes Completing an Ultramarathon

Effects of a Motivational Self-Talk Intervention for Endurance Athletes Completing an Ultramarathon

Decision Rules for Teaching Strategies in Primary Schools: Personality‐treatment Interactions

Employing Behavioral Analysis to Predict User Attitude towards Unwanted Content in Online Social Network Services: The Case of Makkah Region in Saudi Arabia

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