The study has pushed into obscurity any external change in other available alternatives. Presence of other means of transport could also pose a challenge to the consistency of results; other available means may have been made better and hence attracted more people who used to travel by rail. Also, they could have worsened, making more people opt to travel by rail. These factors compounded together make it challenging to determine the external validity.
The timing could as well have influenced the results. The research does not leave out the chances of presence of unusual activities during the period. There are chances of bias on the number of people present depending on the timing of the events. There could have been more people in case the research was done on a peak and also the less number in case it was done on a low season, this would not count as the best sample to represent the results without these considerations.
Factors That Might Limit External Validity of Findings
Lack of uniformity in the study- it is evidently clear that the method used for the whole period under study is not uniform since there was a change from spot check where only random values were obtained with the new method where the exact number count is taken.
Inadequate information about other influencing factors- in order to make sound generalizations, all information should be provided about other factors that could have influenced the research. The research should have provided for any change in other means of transport so as to draw conclusions about their effect on the sector.
