Evaluating Biological Claims to Enhance Critical Thinking through Position Statements.

INTRODUCTION

Historically, critical thinking has been described as the use of good reasoning to make informed decisions (4). The scientific method relies heavily upon good reasoning, both inductive and deductive, as scientists make hypotheses about phenomena, draw conclusions with evidence gathered, and form theories about the world around them (6, 10). Experts have described critical thinking to include analysis, evaluation, forming inferences, as well as having a flexible mindset (5). A scientifically literate person, in addition to having knowledge of particular science content, should be capable of using critical thinking, and the reasoning skills associated with critical thinking, to assess the validity of scientific claims encountered daily.

Critical thinking is seemingly important even outside of academic endeavors. Recent studies have suggested that college students do not learn reasoning skills within their early university years and those with underdeveloped skills in this area are more likely to exhibit poor life outcomes such as unemployment and massive debt post-graduation (2, 3). Because of the importance of students’ critical thinking development, groups such as the National Research Council have described critical thinking as an important 21st century skill to be attained by all students (8).

Research supports student writing as one way to encourage the development of critical thought (7, 11). This teaching tip describes one way to practically integrate critical thinking exercises within college-level or high-school biology courses through the evaluation of biological claims made in the media and/or scientific community.

PROCEDURE

It is recommended that students have at least two opportunities to evaluate scientific claims, one at the beginning of the semester to determine their initial capabilities and allow an opportunity for direct instruction and classroom discussion (pre-), and one later in the semester to assess for change (post-). Due to the structure of the introductory course used to assess this methodology, this occurred within an approximate four-week interval, but it could also be done within a longer time frame. An advantage of this strategy is that many topics within biology relate to real-world issues and there are many scientific claims to be evaluated, allowing these position papers to be easily integrated within the course content.

The instructor should choose a debatable or contested current issue related to course material. We suggest finding an article from the media or popular science publication appropriate for the level of the students. For example, the position paper could involve the avoidance of childhood vaccines due to the parental fear of autism (see Appendix 1 for a sample assignment and Appendix 2 for a sample student response). This can be an in-class assignment of about 30–45 minutes, or a more developed out-of-class homework activity, which could be submitted as an entry to an electronic discussion forum. A sample timeline for completion is found in Appendix 3.

To score the position paper, we used a rubric drafted by our institution and fashioned after the American Association of Colleges and Universities Value Rubric for Critical Thinking and Reasoning, which measures students’ abilities to identify the problem, assess the evidence provided, take a position, and form a conclusion (1) (see Appendix 4). The scores of both raters were compared and differences negotiated to arrive at a final score. The raters included both authors, one of whom taught the class and the other who was not involved in the course. Typically these assignments can be graded by the instructor, or by students in a peer-review process. We used two independent raters to encourage inter-rater reliability and assess any pre-/post- score gains of students. All research conducted complied with relevant federal guidelines and institutional policies (IRB).

Students who have not been exposed to writing of this nature may initially find it challenging to think in a critical fashion. However, after the initial assignment is completed and returned to students, a class discussion concerning each major category within the rubric and student responses can help to develop the required thinking and evaluation processes. The instructor should encourage discussion on critical thinking and skills such as deductive and inductive reasoning and identifying fallacies in claims. Helpful ways to describe critical thinking can be obtained from various sources such as The Partnership for 21st Century Skills (9). In the current course, general discussion of critical thinking amounted to roughly 30 total minutes of class time and about 4 to 5 example problems for each type of skill. As discussion of critical thinking was a supplement to the current course topic and not the main focus, only a small segment of time was utilized. However, such discussion could be extended to a larger facet of the course, or alternatively, students could be given assigned reading to complement their learning in class. Students should be given an opportunity to evaluate a different claim later in the semester to assess the development of their reasoning skills.

DISCUSSION

By incorporating the exercises described in this teaching tip, we found that students enrolled within the introductory biology course (n = 24) described herein demonstrated a significant increase in their ability to assess evidence, one of the critical thinking attributes measured, even within four weeks, when pre-/post- scores were assessed using the Wilcoxon signed rank test (alpha = 0.05; p = 0.004) (see Fig. 1). While students’ scores within other categories of our critical thinking rubric may not have significantly changed, one can imagine that over a longer period of time or more assignments, there may be more significant change within these realms as students gain more practice (12).

FIGURE 1.

Assessment of critical thinking through position statements in an undergraduate biology course.

CONCLUSION

Critical thinking is an important skill for students to learn. Opportunities to develop this skill can be easily implemented within biology courses through writing. In our study, a focused discussion after the first writing assignment led to improved performance when evaluating claims on a later but similar assignment. These findings support the notion that even brief learning experiences involving critical thinking improve students’ higher order thinking as they assess scientific evidence.

Appendix 1: Sample assignment

Appendix 2: Sample student response

Appendix 3: Sample timeline for completion

Appendix 4: Rubric to assess students’ critical thinking skills