Diagnostic of students' misconceptions using the Biological Concepts Instrument (BCI): A method for conducting an educational needs assessment

Concept inventories, constructed based on an analysis of students’ thinking and their explanations of scientific situations, serve as diagnostics for identifying misconceptions and logical inconsistencies and provide data that can help direct curricular reforms. In the current project, we distributed the Biological Concepts Instrument (BCI) to 17-18-year-old students attending the highest track of the Swiss school system (Gymnasium). Students’ performances on many questions related to evolution, genetics, molecular properties and functions were diverse. Important common misunderstandings were identified in the areas of evolutionary processes, molecular properties and an appreciation of stochastic processes in biological systems. Our observations provide further evidence that the BCI is efficient in identifying specific areas where targeted instruction is required. Based on these observations we have initiated changes at several levels to reconsider how biological systems are presented to university biology studies with the goal of improving student’s foundational understanding.


Students' Performance Comparisons
The significant differences between groups of participants are shown in Figure S1. There was no significant difference in the distribution of individual students' scores between the two cohorts (Kruskal-Wallis, χ 2 (df = 1) = 0.153, p-value = 0.696, alpha < 0.05) ( Figure S1-A). The point in the semester when the BCI was administered did not affect students' BCI scores. More precisely, the performances of participants who have completed the BCI in June, after instruction, were not significantly higher than students who have completed the questionnaire earlier in the semester (essentially before instruction) ( Figure S1-B and S1-C  Consequently, the participants' knowledge was consistent with some standardized Swiss criteria. However, for confidentiality reasons, those questions cannot be shown in the current report.

Results on all BCI questions
1-Many types of house plants droop when they have not been watered and quickly "straighten up" after watering. The reason that they change shape after watering is because ...

Answer
Percentage answering (%) a-Water reacts with, and stiffens, their cell walls.
2.9 b-Water is used to generate energy that moves the plant.

39.4
c-one parent was heterozygous, the other was homozygous for the gene that controls the trait.

29.5
d-a recombination event has occurred in one or both parents.

8.8
NA-No answer 1.1 7-You are doing experiments to test whether a specific type of acupuncture works. This type of acupuncture holds that specific needle insertion points influence specific parts of the body. As part of your experimental design, you randomize your treatments so that some people get acupuncture needles inserted into the "correct" sites and others into "incorrect" sites. What is the point of inserting needles into incorrect places? Answers Percentage answering (%) a-It serves as a negative control. 72.4 b-It serves as a positive control.
12.0 c-It controls for whether the person can feel the needle.
3.6 d-It controls for whether needles are necessary 11.2 NA-No answer 0.8 8-As part of your experiments on the scientific validity of this particular type of acupuncture, it would be important to ... Answers Percentage answering (%) a-test only people who believe in acupuncture.
2.3 b-test only people without opinions, pro or con, about acupuncture.

30.9
c-have the study performed by researchers who believe in this form of acupuncture. 0.6 d-determine whether placing needles in different places produces different results.

65.9
NA-No answer 0.2 9-What makes DNA a good place to store information? Answers Percentage answering (%) a-The hydrogen bonds that hold it together are very stable and difficult to break. 10-What is it about nucleic acids that makes copying genetic information straightforward? Answers Percentage answering (%) a-Hydrogen bonds are easily broken.
10.5 b-The binding of bases to one another is specific.
60.0 c-The sequence of bases encodes information.
25.1 d-The shape of the molecule is determined by the information it contains.

3.8
NA-No answer 0.6 11-It is often the case that a structure (such as a functional eye) is lost during the course of evolution. This is because ... Answers Percentage answering (%) a-It is no longer actively used. 33.7 b-Mutations accumulate that disrupt its function. 21.5 c-It interferes with other traits and functions.
2.5 d-The cost to maintain it is not justified by the benefits it brings.

40.8
NA Answers Percentage answering (%) a-It is stronger than a recessive form of the trait. 39.6 b-It is due to more, or a more active gene product than is the recessive trait.
7.6 c-The trait associated with the allele is present whenever the allele is present.

43.4
d-The allele associated with the trait inactivates the products of recessive alleles.

7.6
NA-No answer 1.9 15-How does a molecule bind to its correct partner and avoid "incorrect" interactions? Answers Percentage answering (%) a-The two molecules send signals to each other.
2.3 b-The molecules have sensors that check for "incorrect" bindings.

5.5
c-Correct binding results in lower energy than incorrect binding. 20-Imagine an ADP molecule inside a bacterial cell. Which best describes how it would manage to "find" an ATP synthase so that it could become an ATP molecule? Answers Percentage answering (%) a-The ATP synthase would grab it.
8.6 b-Its electronegativity would attract it to the ATP synthase.

38.7
c-It would be actively pumped to the right area.
23.8 d-Random movements would bring it to the ATP synthase.

24.0
NA-No answer 4.8 21-You follow the frequency of a particular version of a gene in a population of asexual organisms. Over time, you find that this version of the gene disappears from the population. Its disappearance is presumably due to ... Answers Percentage answering (%) a-genetic drift.
28.6 b-its effects on reproductive success. 35.6 c-its mutation.
27.2 d-the randomness of survival. 14.1 b-Both involve passing through a barrier.
12.2 c-Both involve random events without regard to ultimate outcome.

24.6
d-They are not alike. Genetic drift is random; diffusion typically has a direction.