TABLE 6.

Sample student responses in using sources to critically evaluate results.

Grade	Sample Responses
Fail	Student text: “Aas et al. (2005) attempted to define the normal oral bacterial flora (1), and the only similar bacteria found were of the Streptococcus group while others were not found within our techniques. Our list may be different from the article due to the different sampling method as well as the health of sample provider.” Justification: Incorrect comparison between cited study and own experiments; failure to describe differences in taxa detected in detail; omission of methodology employed in cited study (sample size, culture-dependent/independent protocols, demographics of volunteers).
Pass	Student text: “Aas et al. (2005) performed a similar experiment to the present one (1). They reported that species from the genera Gemella, Granulicatella, and Streptococcus were present on the dorsal tongue of the majority of subjects. These results are in accord with data from the present study, as species from these genera were found in greater than 80% of subjects here. Species from the genera Gemella, Granulicatella, and Streptococcus were found in more than 80% of subjects’ oral cavities in our culture-independent tests. However, only Streptococcus was positively identified using culture-dependent methods. Aas et al. (2005) used 16S rRNA sequencing in their experiment, making their methods quite similar to the process used by us in the culture-independent part of our study. Therefore, it is expected that these results would be more comparable than our culture-dependent data and Aas et al.’s data.” Justification: Valid and sufficiently detailed comparison made between cited study and own experiments, both in taxa detected and identification protocols; omission of sample size, demographic data of volunteers.
High Pass	Student text: “Research by Keijser and colleagues (2008) aimed to determine the number of different phyla and abundance of oral microflora in healthy adults (16), similar to this experiment and other studies (15). The vast majority of sequences (99.6%) belonged to one of seven phyla, all of which are common gastrointestinal flora with varying metabolic functions: Actinobacteria, Bacteroides, Firmicutes, Fusobacteria, Proteobacteria, Spirochetes and Phylum TM7. This is similar to results from this experiment. At a genus level Streptococcus, Veillonella, Prevotella, Corynebacterium and Actinomyces were identified as the predominant genera in saliva (16). This experiment found support for the seven main phyla and main genera suggested by previous research. Staphylococcus was found in culture-dependent but not in culture-independent techniques in this experiment; however, this was not supported in the literature. This could suggest that it should not be present, as in culture-independent methods. In this experiment a larger sample size was employed; however, data could vary due to individual differences such as socio-economic status, age, geolocation and health status rather than sample size. Antibiotics may interfere with the number of bacteria found in both techniques, which may impact this experiment (15). Culture-dependent methods may have been restricted due to lack of essential nutrients and growth factors from media, production of inhibitory substance by other bacteria and metabolic dependence on other species for growth (25).” Justification: Valid and sufficiently detailed comparison made between cited study and own experiments, both in taxa detected and identification protocols; in-depth discussion of sample population demographic factors that may influence experimental outcomes.