Background:

develop learning assessmentsThe purpose of this assignment was to develop activities to assess whether students in FSHN 350 have gained adequate knowledge to meet the specific objectives below.

Lipids objectives:

Conditions: Given a structural drawing of any of the following fatty acids: myristic, palmitic, stearic, oleic, α-linolenic, linoleic, arachidonic, eicosapentaenoic, and docosahexaenoic -or- given the two fatty essential acids α-linolenic acid and linoleic acid.
Criteria/Standards: Using principles of essentiality, elongation and desaturation, the Common, Delta, and Omega naming systems, and an understanding of the differences between n-6 and n-3 fatty acids.
  1. Identify the fatty acid using each of the naming systems
  2. Describe its level of saturation
  3. Locate all of its double bonds
  4. Classify it as cis or trans
  5. Explain why each is essential.
  6. Describe the type of PUFAs that can be formed from each, and list an example.
  7. Explain why linoleic acid cannot be converted to α-linolenic acid) in the body.
  8. Contrast the physiology of the two fatty acids (and other fatty acids in their group) and speculate what the impact might be on health when consuming a diet rich in one type versus the other.

In general, how learning will be assessed for these objectives:

Criterion referenced-developed questions to determine learners’ competence on particular objectives.

The activities/instruments that will be used in the learning assessment are:

  1. An online quiz with questions selected randomly from a quiz bank (including graphics of the molecular structures of nine fatty acids). Quiz questions will cover the same material covered on the exam for that section. They will be a combination of matching, multiple-choice, with ≥5 options, fill-ins, and short answer/essay. Students will be allowed three opportunities to take each quiz and will be allowed to keep the best score.
  2. An exam with similar questions—covering the same concepts, but not the exact questions. The exam would also ask questions at higher levels of Bloom’s taxonomy.

Why the particular assessments were chosen:

  • Online quizzes will follow lectures on the topic and will provide students with more than one opportunity to be assessed for the material. Essentially, the online quiz will provide students a tool to learn/review the material covered in lecture (using whatever materials they have available—book, notes, the web).
  • An example quiz may be 10 questions and students will be allowed 20 minutes to complete them (i.e. two minutes/question). Therefore, a student may take the quiz the first time and realize that there is not enough time to look up the answers to the questions in their book and notes. Even if they perform poorly, however, they can go back and review the material covered and try again.
  • Most important, the quiz will provide students the chance to learn and be assessed on the material at lower levels of Bloom’s taxonomy (compared with the exam).
  • Exams will have similar questions, but may cover the material at a higher level. Additional short answer and essay questions will be asked to assess the students’ knowledge (without allowing guessing like on matching or multiple-choice).

The specific types of questions that will be asked to assess each objective (and why each was chosen) are discussed below. Expand for details and example assessment.

Objective 1: Identify the fatty acid using each of the naming systems:

For this objective, a student must look at a molecular drawing of any of the nine fatty acids and be able to provide its common name, its Delta name, and its Omega name.  On a quiz, the molecular drawing(s) of a fatty acid would be shown, and many different types of questions could be asked.

Matching questions: the molecular drawing of several of the nine fatty acids would be shown in the left column, and the right column would include a list of 9-27 choices. Students would need to be able to match the Common, Delta, and/or Omega name to the correct structure. Correctly answering the questions by guessing would be difficult due to the number of choices.

Multiple-choice questions: The student must identify the fatty acid from a list. However, the list may include any combination of the nine common names, the nine Delta names, and the nine Omega names. This would be similar to the matching section. However, incorrect answers could be included as choices, reducing the chance that students could guess by process of elimination.

Fill in the blank questions: The student would be provided the structural drawing and would need to provide its name(s) using the standard naming systems. This would require more than simple recall of a common name. To identify a fatty acid, the student would need to be able to 1) count the number of carbons in the fatty acid structure and recall any/all fatty acids with that number of carbons; 2) to identify the location of each of the double bonds in the structure, which would require them to understand the difference between the Omega and Delta end of the fatty acid by looking at the structure and how to properly count from either end, and finally, 3) they must understand each naming convention to be able to write out the name appropriately.

Objectives 2-4: Identify the fatty acid using each of the naming systems:
Objective 2: Describe its level of saturation
Objective 3: Locate all of its double bonds
Objective 4: Classify it as cis or trans.

Multiple-choice questions would be used to assess each of these three objectives. The student must review the structural drawing and classify the fatty acid as saturated, monounsaturated, or polyunsaturated; specify the location of each double bond by the carbon number; and, if it is unsaturated, choose whether it is cis- or trans-unsaturated. This is important background (lower-level) knowledge that is required to understand the more complex concepts covered later in the section. Because there are only a few possible choices for questions about each of these objectives, it would be easier for students to guess and get them right. Thus, bogus words could be introduced (e.g. mono-saturated or poly-saturated) as choices or, alternatively, a single question could be asked to assess all three of these objectives at once. For example, multiple structures could be shown and the question could ask, e.g.: Which of the pictured structures is trans-unsaturated with one double bond?

Objective 5: Explain why each is essential.
The purpose of this objective is for students to understand:

  1. Characteristics of nutrients that are considered essential: a) they promote a biological function, b) inadequate intake may lead to deficiency symptoms with severity proportional to shortfall, and c) deficiency is reversed only by consuming the essential nutrient or its precursor, and
  2. Why α-linolenic and linoleic acid are considered essential fatty acids.

Questions to assess students’ knowledge would likely be short answer or essay questions. The first purpose of this objective is part of the very first section of the course and would have already been covered in assessments during that section. Therefore, students would be expected to understand purpose one already and build upon that. A short answer or essay question would ask the students to EXPLAIN purpose #2, e.g. by describing/contrasting the general biological functions of each linolenic and linoleic acid and the general group of fatty acids derived from them—n3 and n6 fatty acids, respectively.

Objective 6: Describe the type of PUFAs that can be formed from each, and list an example

As an extension of Objective #5, students must further describe n3 and n6 fatty acids (structure and function). Again, questions to assess students’ knowledge would likely be short answer or essay questions. Students should be able to specifically write down the group to which each of the two essential fatty acids belongs and then name an additional fatty acid from the group. This could also be a fill in the blank question.

Objective 7: Explain why linoleic acid cannot be converted to α-linolenic acid in the body.

Students should understand and be able to write down why these fatty acids cannot be converted one into the other, and the objective should likely be modified to add a second part—to explain why neither can be synthesized from other fatty acids. Questions to assess students’ knowledge would be short answer or essay questions that would require them to EXPLAIN the reasons.

Objective 8: Contrast the physiology of the two fatty acids (and others in their group)...
…and speculate what the impact might be on health when consuming a diet rich in one type vs. the other.

The student must write an essay, assimilating their understanding of the opposing functions of n3 and n6 fatty acids, including the idea that consuming foods with more n3 or n6 would promote one function versus the other, and then they would propose (based on the studies discussed in class) what the impact might be on health.