e. Was the manipulated variable applied to students individually or in groups?

A group of individuals was selected for the manipulated variable, concept mapping. Individuals, however, created concept maps and completed pre-tests and post-tests.

f. What additional detail could be provided about how the pre and posttest were administered?

Although the authors write that the tests were time intensive, readers want to know how long completing these tests took. In addition, readers want to know what the environment was like for taking the test. Could students have been distracted? Were they allowed to consult with their groups? Could they have cheated? Samples of the discussion questions, perhaps in an appendix, would also have been appropriate.

g. What information could be provided to address the possible and plausible threats to internal validity?

First, the researchers need to be more clear regarding the students' situation in groups and when collaboration was allowed and when it was not. Researchers need to also address the possibility of student's...

Were students able to receive instructions in their native languages? Was sheltered instruction used when administering the tests and teaching concept mapping, etc.
h. What limitations to this study could be emphasized?

Although the students that were selected exhibited different ability levels, ages, and sexes, they were all from the same school. Also, this school was an elite center located at a University.

Readers must ask themselves if these results could be applied to the ESL learner in the public school. Also, the students were only as old as 22. Is it possible that these results could be applied to older ESL students?

i. What steps could be taken for the researchers to increase generalizability?

While this study is an important first step, the researchers can increase generalizability by determining whether or not they can replicate results in different institutions, including public schools. Also, researchers should perform the study again with learners of much younger and much older ages.