Teaching to the Test…or Testing to Teach: Exams Requiring Higher Order Thinking Skills Encourage Greater Conceptual Understanding

Abstract

In order to test the effect of exam-question level on fostering student conceptual understanding, low-level and high-level quizzes and exams were administered in two sections of an introductory biology course. Each section was taught in a high-level inquiry based style but was assigned either low-level questions (memory oriented) on the quizzes and exams, or high-level questions (application, evaluation, and analysis) on the quizzes and exams for the entirety of the semester. A final exam consisting of 20 low-level and 21 high-level questions was given to both sections. We considered several theoretical perspectives based on testing effect, test expectancy, and transfer-appropriate processing literature as well as the theoretical underpinnings of Bloom’s taxonomy. Reasoning from these theoretical perspectives, we predicted that high-level exams would encourage not only deeper processing of the information by students in preparation for the exam but also better memory for the core information (learned in the service of preparing for high-level questions). Results confirmed this prediction, with students in the high-level exam condition demonstrating higher performance on both the low-level final-exam items and the high-level final exam items. This pattern suggests that students who are tested throughout the semester with high-level questions acquire deep conceptual understanding of the material and better memory for the course information, and lends support to the proposed hierarchical nature of Bloom’s taxonomy.

Appendix

Sample Test Items

Low-Level Unit Exam Items

Term/Concept: Haploid/Meiosis

• i. In humans, the haploid number, n equals:

  • a) 2n.

  • b) 44.

  • c) 23.

  • d) 46.

Term/Concept: Nondisjunction/Meiosis

• ii. Trisomy is a consequence of _______________________, the unequal distribution of chromosomes during meiosis.

  • a) recombination

  • b) cytokinesis

  • c) nondisjunction

  • d) crossing over

Term/Concept: Types of Selection/Evolution

• iii. Divergent selection occurs when:

  • a) low-ranking, “sneaker” males disrupt the mating between a dominant female and a male.

  • b) individuals with one extreme value of a trait have greater fitness than individuals with the other extreme value of the trait.

  • c) individuals with extreme values of a trait have greater fitness than individuals with intermediate values of the trait.

  • d) there is selection against the extreme ends of a trait’s distribution.

Term/Concept: Hardy–Weinberg Equilibrium/Microevolution

The pygmies are a group of humans who are thought to have lived continuously in the rainforest of central Africa since the ice age, in geographically separated areas called refuges. There are two distinct groups of pygmies, the eastern and the western, living in two different refuges. The eastern population has an HbS allele frequency of 8 %. The western population has an HbS allele frequency of 18 %.

• iv. Are the eastern and western pygmies in Hardy–Weinberg equilibrium?

  • a) Yes

  • b) No

  • c) Impossible to tell

Term/Concept: Predicted Allelic Frequencies/Microevolution

• v. Given the HbS allele frequency in the western population is 0.18 (q), what is the frequency of the normal allele (HbA) in the western population?

  • a) 0.2

  • b) 0.18

  • c) 0.82

  • d) 0.08

Term/Concept: Interpreting the Periodic Table/Atomic theory

• vi. Looking at the figure to the right, how many protons does chlorine have?

  • a) 17

  • b) 18

  • c) 35.5

  • d) 71

  

Term/Concept: Electron Shells/Atomic Bonding

• vii. If the normal electron-shell diagram of Sodium (Na) is pictured to the right, what does Na⁺ look like?

  

Low-level Final Exam Items

Term/Concept: Types of Bonds/Atomic bonding

• viii. ____________ bonds deal with the sharing of electrons, while __________bonds deal with the transferring of electrons completely to another atom.

  • a) Ionic, Hydrogen

  • b) Ionic, Covalent

  • c) Covalent, Hydrogen

  • d) Covalent, Ionic

  • e) Hydrogen, Covalent

  • f) Hydrogen, Ionic

Term/Concept: G1/Cell Cycle

• ix. Within a Eukaryotic cell cycle, the primary stage during which normal cellular functioning occurs is

  • a) G1

  • b) S

  • c) G2

  • d) Mitosis

  • e) Meiosis

Term/Concept: Hardy–Weinberg Equilibrium/Microevolution

• x. Which of the following violations to Hardy–Weinberg assumptions would be most likely to change the allele frequency of a small population of pigmy monkeys living on an island?

  • a) Mutation

  • b) Changing environment

  • c) Genetic drift

  • d) Gene flow

  • e) Selection

  • f) Non-random mating

  • g) All of the above have an equal chance of moving the population out of Hardy–Weinberg equilibrium.

High-Level Unit Exam Items

Term/Concept: Haploid/Meiosis

You and your spouse are expecting your first child. Because you and your spouse have an extensive history of genetic diseases on both sides of the family, you are concerned about the health of your unborn baby and request that an amniocentesis be performed so that you can prepare yourself for whatever lies ahead. During this procedure, a large needle is inserted through the mother’s belly and into the amniotic sack in order to collect a sample of amniotic fluid containing sloughed cells from the embryo. These cells are then grown in a laboratory for about a week in order to analyze the chromosomes.

• xi. The DNA from a typical human sperm cell weighs approximately 3.3 picograms (a picogram is a 10⁻¹² g). If all chromosomes weighed approximately the same, how much does a typical chromosome weigh?

  • a) 0.07 picograms

  • b) 0.14 picograms

  • c) 0.28 picograms

  • d) 75.9 picograms

  • e) 151.8 picograms

Term/Concept: Nondisjunction/Meiosis

• xii. Doctors find that in the majority of embryo’s cells, the DNA weighs nearly 6.8 picograms. What is a possible explanation for this?

  • a) The embryonic cells remained haploid, meaning that the sperm’s chromosomes never fused with the egg’s and were most likely kicked out with the polar body.

  • b) The embryonic cells contain all duplicated chromosomes; thus, there must be a problem with Meiosis II and sister chromatids are never separating.

  • c) The embryonic cells contain extra DNA indicating a possible trisomy.

  • d) The embryo is normal but is definitely a girl, since girls carry an extra X chromosome.

Term/Concept: Types of Selection/Evolution

Zawicki and Witas (2007) studied the C-C chemokine receptor 5 (CCR5), a receptor on the white blood cell that is used by many pathogens to gain access to the cell, including HIV, Bubonic plague, and others. It has been found that a mutation (the deletion of 32 base pairs; designated CCR5-D32) prevents HIV from entering the cell. Individuals who are homozygous for the CCR5-D32 mutation are nearly completely resistant to HIV infection and individuals who are heterozygous have slower disease progression and better survival rates.

• xiii. There are no known disadvantages to being homozygous for the CCR5-D32 mutation. Predict what type of selection will most likely occur, given enough time?

  • a) Stabilizing

  • b) Directional

  • c) Diversifying

Term/Concept: Hardy–Weinberg Equilibrium/Microevolution

• xiv. Scientists have found a high incidence of this allele in European and Mediterranean people. The frequency of the CCR5-D32 allele on the European continent is 10 %. What percentage of the people are likely carriers of the CCR5-D32 allele?

  • a) 90 %

  • b) 10 %

  • c) 18 %

  • d) 9 %

Term/Concept: Predicted Allelic Frequencies/Microevolution

• xv. Given that the CCR5-Δ32 allele confers immunity to the bubonic plague, which of the following phenomena would you predict?

  • a) The bubonic plague of the 14 ^th century would closely correspond in geographic distribution as well as timing with the suspected origin and increasing frequency of the CCR5- Δ32 mutation.

  • b) The bubonic plague of the 14^th century would directly precede (come before) the emergence of the CCR5- Δ32 mutation in the same geographic distribution indicating that the plague caused the mutation of the CCR5 receptor.

  • c) The bubonic plague of the 14^th century would be only in geographic areas where the CCR5- Δ32 mutation was not prevalent since those are the people most susceptible to plague infection.

  • d) The bubonic plague of the 14^th century would have emerged shortly after and in the same geographic location as the emergence and increasing frequency of the CCR5- Δ32 mutation indicating that the CCR5- Δ32 mutation increases plague infection rate.

Term/Concept: Electron Shells/Atomic Bonding

A salt is defined as “a compound resulting from the formation of an ionic bond; also called an ionic compound” (Campbell & Reece, 2005). That means that a salt can be formed from any two ions. Below are the electron-shell diagrams of magnesium (Mg) and chlorine (Cl).

• xvi. If table salt (the kind you eat) is sodium chloride (NaCl), what is the molecular formula of magnesium chloride?

  • a) MgCl

  • b) Mg₂Cl

  • c) MgCl ₂

  • d) Mg₂Cl₂

High-Level Final Exam Items

Term/Concept: Predicting Selection/Microevolution

• xvii. The incidence of spinal muscular atrophy (an autosomal recessive disease) in the United States is about 1 case in every 17,000. Whereas, in North Dakota, the prevalence is 1 in 6720. Which of the following would support the hypothesis that genetic drift was responsible for the increased allele frequency in North Dakota?

  • a) There is an abnormally high concentration of mutagenic chemicals in the ground water causing an increased mutation rate in North Dakota.

  • b) One of the best treatment centers for SMA is located in North Dakota causing migration of SMA carriers into the area at an abnormally high frequency.

  • c) The original settlers of North Dakota were a small group of pioneers who happened to have an abnormally high frequency of the SMA allele in their population.

  • d) A particular mosquito-born parasite native to North Dakota causes high infant mortality; carriers of the SMA allele are less likely to catch the disease.

Term/Concept: Electron Shells/Atomic Bonding

The hydrogen car runs off the power of hydrogen created from water in the process of electrolysis (i.e., the splitting of water). In this process, water is split into hydrogen and oxygen gases by running an electrical current through the water. This is done by placing two metal rods in the water and attaching them to an electrical source. The cathode donates electrons to the solution; whereas the anode accepts electrons from the solution. The reactions at each node are shown below (keep in mind that these reactions are happening at the same time):

At the Cathode, where hydrogen gas bubbles are produced: 2H⁺ + 2e^- → H₂ (gas)

At the Anode, where oxygen gas bubbles are produced: 2H₂O → O₂ (gas) + 4H⁺ + 4e^-

• xviii. How many electrons must come from an outside source (like the anode or cathode) to make this reaction run?

  • a) Two electrons are being donated by the cathode

  • b) Two electrons are being donated by the anode

  • c) Four electrons are being donated by the anode

  • d) Eight electrons are being donated by the anode

  • e) No electrons are being donated, they are all contained within the original water molecule

Term/Concept: Homologous Chromosomes/Meiosis

• xix. Cystic fibrosis, an autosomal recessive disease, is located on chromosome #7. If you viewed the 7^th chromosome pair of an individual who is a carrier for cystic fibrosis during prophase of mitosis, which of the following is the best representation of what you would see?

  

Term/Concept: Interpreting the Periodic Table/Atomic Theory

• xx. Let’s say I have a hypothetical element, called “Element J.” It tends to make three bonds and the most common isotope has 3 more neutrons than protons. Which of the following is the most accurate representation of Element J?