| Literature DB >> 23222836 |
Masha Tsaushu1, Tali Tal, Ornit Sagy, Yael Kali, Shimon Gepstein, Dan Zilberstein.
Abstract
This study offers an innovative and sustainable instructional model for an introductory undergraduate course. The model was gradually implemented during 3 yr in a research university in a large-lecture biology course that enrolled biology majors and nonmajors. It gives priority to sources not used enough to enhance active learning in higher education: technology and the students themselves. Most of the lectures were replaced with continuous individual learning and 1-mo group learning of one topic, both supported by an interactive online tutorial. Assessment included open-ended complex questions requiring higher-order thinking skills that were added to the traditional multiple-choice (MC) exam. Analysis of students' outcomes indicates no significant difference among the three intervention versions in the MC questions of the exam, while students who took part in active-learning groups at the advanced version of the model had significantly higher scores in the more demanding open-ended questions compared with their counterparts. We believe that social-constructivist learning of one topic during 1 mo has significantly contributed to student deep learning across topics. It developed a biological discourse, which is more typical to advanced stages of learning biology, and changed the image of instructors from "knowledge transmitters" to "role model scientists."Entities:
Mesh:
Year: 2012 PMID: 23222836 PMCID: PMC3516796 DOI: 10.1187/cbe.12-04-0042
Source DB: PubMed Journal: CBE Life Sci Educ ISSN: 1931-7913 Impact factor: 3.325
Design of the instructional change
| Preintervention | Intervention | |||
|---|---|---|---|---|
| Traditional | Traditional plus tutorial | Adapted teaching | Active learning | |
| Tutorial | − | + | + | + |
| Lectures | + | + | + Adapted: focus on chosen wide-scope issues | Reduced to 30% |
| Small-group learning | − | − | − | + |
| Learning pattern | Passive only | Passive and individual–interactive (with tutorial) | Passive and individual–interactive (with tutorial) | Active individual and group; interactive (with tutorial) |
| Student assessment | Final MC exam | Final MC exam and O-HOT questions | Final MC exam and O-HOT questions; team's presentation | |
Example of group-learning topics and subtopics
| Group topics | Team subtopics |
|---|---|
| Eukaryotic cell | Chloroplast |
| Mitochondria | |
| Lysosome | |
| Golgi apparatus | |
| Eukaryotic cell complexity | |
| Cellular membrane | Composition and structure |
| Passive transport | |
| Active transport | |
| Endo- and exocytosis | |
| Signal transduction |
Figure 1.Timetable for the group learning in the active-learning version.
An example of a driving question for the onset of team work
| Protein degradation—Where have the mice brain proteins gone? |
|---|
| It is possible to track body materials in vivo by labeling them using radioactive isotopes. This approach is based on the fact that radioactive isotopes are processed as are natural substances (e.g., amino acids in proteins). The advantage of this method is that radiolabeled compounds can be detected using scintillation counters. |
| A researcher fed mice with [14C]-labeled lysine (note that the half-life time 14C is 5770 yr). He expected that after some time most mice proteins would contain the radiolabeled lysine and that the level of radioactivity in mice proteins would be proportional to the amount of [14C]lysine in tissues. The mice mated and reproduced. Females kept on eating radioactive food throughout pregnancy (∼3 wk) and nursing (∼3 wk). Their offspring ate [14C]lysine until maturity (∼60 d), at which time all body proteins became radioactive. When the offspring were 60-d old, radioactive food was replaced by normal food. Once radioactive food was not available, mice started to synthesize radioactive-free proteins. |
| Subsequently, at time intervals after shifting to normal food, mice were scarified, and the level of radioactivity in brain tissues was monitored. Results are illustrated in the following graph: |
| When preparing your team presentation, please refer to the following questions: |
| 1. How can you explain the results of the experiment? |
| 2. Why is it reasonable to assume that protein degradation did not happen in lysosomes? |
| 3. What is the link between ubiquitin, a protein discovered by Technion Nobel laureates Hershko and Ciechanover, and the phenomenon described in the graph? |
| A question you should consider, but not necessarily include in your presentation: Is it possible that the observed decrease in radioactivity was the result of natural degradation of 14C? |
Course versions and data collection sample for statistical analysis (n = 569)
| 2009 | 2010 | 2011 | |||
|---|---|---|---|---|---|
| Approach | Springa | Wintera | Spring | Winter | Spring |
| Traditional plus tutorial | — | — | 61 | 77 | 171 |
| Adapted teaching | 44 | 162 | |||
| Active learning | 28 | 26 | |||
aThe consecutive semesters Spring 2009 and Winter 2010 are presented only to indicate the teaching version, although we do not present student data from these semesters.
An example of open-ended questions added to the final exam and the thinking skills they require
| Cyclin-dependent kinase (Cdk1) is a protein that is active in phase M of the cell cycle. The figure shows Cdk1 activity levels during several cell cycles and also the concentrations of Cyclin B and Cdk1. | |
| Skill | Questions |
| Evidence-based argumentation | 1. Based on the above data and your knowledge of cell cycle regulatory system, describe the interaction between these two proteins and how it affects the cell cycle. |
| Describing a mechanism doing near transfer | 2. Other regulatory mechanisms in which protein X can affect protein Y activity are known in living cells. Explain one. |
| Evidence-based argumentation | 3. Proteins can be regulated at the RNA and at the protein level. Which of them is the true one for Cdk1 regulation? |
| Articulating a biological principle doing near transfer | 4. Retinoblastoma protein (RB) is a substrate of the cyclin-Cdk complex. The reaction product is a phosphorylated RB. Separation of RB from the total cell proteins results in a mixture of phosphorylated and nonphosphorylated RB molecules. Describe an experiment that measures phosphorylated RB concentration. |
Figure 2.Student questions of various cognitive levels in two topics asked in the adapted-teaching version (Spring 2010) and before intervention (Spring 2008).
Figure 3.Achievements of students studying in the adapted-teaching version (attended class) vs. these studying in the traditional-plus-tutorial version (did not attend class) in Spring 2010.
Figure 4.Student performance in the open-ended questions across the three versions of the course (Winter 2011).
Student O-HOT questions scores in the active-learning (experimental) version vs. the traditional-plus-tutorial (comparison) version
| Active learning | Traditional plus tutorial | ||||||
|---|---|---|---|---|---|---|---|
| Version | Mean score (SD) | Mean score (SD) | Effect size | ||||
| Winter 2011 | 34.6 (22.6) | 28 | 23.5 (21.7) | 42 | 2.05 | 0.04 | 0.24 |
| Spring 2011 | 61.6 (24.3) | 26 | 50.4 (25.8) | 171 | 2.08 | 0.04 | 0.22 |