Does An Additional Instructional Hour Make a Difference?

Submitted by Jim Waugh on
Duration
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What is the Purpose of the Assessment?

BIO201 is difficult, student preparedness is essential.  Preparation typically comes from a student’s taking one of four prerequisites BIO156, BIO156XT, BIO181, or BIO181XT.  The XT classes included 50 additional minutes of instruction per week.  The assessment question seeks to answer if additional class time made a difference in student success in BIO201.

Describe the necessity for this assessment

The additional class time provides the instructor more time to reinforce student learning but it comes at a cost, students are paying for an additional credit hour of instruction.  Instructor availability and cost for that additional hour may affect EMCC course scheduling.  This assessment seeks to provide insight as to whether the additional instruction made a statistically significant difference in student performance.  With this data, EMCC may make more informed decisions on future scheduling of XT classes in order to maximize student success within the constraints of student budgets, EMCC budgets, faculty availability, etc.

Describe how the practice will be implemented

To understand the prerequisite impact on BIO201, we needed to understand the degree of success within each of the prerequisites and also the degree of success in BIO201, comparing the outcomes of students taking one of those prerequisites.  

Students who successfully completed (Grade of A, B, C, P) the prerequisites (BIO156, BIO156XT, BIO181, or BIO181XT) and attempted BIO201:

  • BIO156-BIO201: 951 students

  • BIO156XT-BIO201: 35 students

  • BIO181-BIO201: 80 students

  • BIO181XT-BIO201: 29 students

Data was pulled by OPIE (via Tableau Desktop) for all students since fall 2018 who had taken BIO156, BIO156XT, BIO181, BIL181XT, and BIO201.  

  • The enrollment data was filtered to only include data for students who took at least one of the prerequisites and completed BIO201.
  • Success is defined as a student earning a grade of A, B, C, or P.  Those students were scored as having a “1” score.  Students who failed (D, F) or withdrew were given a score of “0”.
  • Testing was based on the average scores, using Excel’s (Analysis Toolpak) t-Test: Two-sample assuming unequal variances.  This approach is “a statistical test used to compare the means of two independent groups when you suspect that the populations they are drawn from have different variances (i.e., different levels of spread in the data), also commonly known as a "Welch's t-test" in statistics; it allows you to test if there is a significant difference between the means of the two groups even if their variances are not equal.”)

The first series of tests compared each of the prerequisites against each other to see if one had a statistically significant higher mean (was one average higher than the other at a statistically significant level).  The hypothesis assumed the difference was 0, with an alpha of 0.05 (“The alpha level, also known as the significance level, is the probability of incorrectly rejecting the null hypothesis when it is true. The alpha level is a value that the researcher chooses to determine the risk of making a Type I error, or false positive).  The goal of this testing is to determine if one is higher with significance so a one-tailed test was utilized for this analysis.

Testing pairs included:

  • BIO156 to BIO156XT
  • BIO156 to BIO181
  • BIO156 to BIO181XT
  • BIO156XT to BIO181
  • BIO156XT to BIO181XT
  • BIO181 to BIO181XT

The second set of tests sought to see if there was a difference in BIO201 scores based on the successful completion of each of the prerequisites using the same testing as mentioned above.  This time the data included those students who were successful (ABCP) in a prerequisite and completed BIO 201 (either a score of “1” (A, B, C, P) or “0” (D, F, W, Y, Z).  

Testing pairs included:

  • Completed BIO201, successful in BIO156 vs successful in BIO156XT
  • Completed BIO201, successful in BIO156 vs successful in BIO181
  • Completed BIO201, successful in BIO156 vs successful in BIO181XT
  • Completed BIO201, successful in BIO156XT vs successful in BIO181
  • Completed BIO201, successful in BIO156XT vs successful in BIO181XT
  • Completed BIO201, successful in BIO181 vs successful in BIO181XT

Regression analysis of potential independent variables was performed but not included in this report, given the limited number of observations for BIO156XT and BIO181XT.

Interpret, compare, and describe the results

Initial comparison: the % successful between the various prerequisites

  • BIO156 to BIO181 – statistically significant difference (P(T<=t) one-tail =0.0032) .  The number of observations for each is relatively high (BIO156=2014, BIO181=3536), making the comparison worthy of consideration.  The success rate of BIO156 is higher than BIO181 at a statistically significant level (BIO156=70%, BIO181=66%).  Potential causes may be related to the preparedness of students upon entering the class as well as the instructor expectations of student performance in each course.
  • BIO156 to BIO156XT – no statistically significant difference
  • BIO156 to BIO181XT – no statistically significant difference
  • BIO156XT to BIO181 – no statistically significant difference 
  • BIO156XT to BIO181XT – no statistically significant difference
  • BIO181 to BIO181XT– no statistically significant difference

The second comparison compared the outcomes in BIO201 based upon having successfully completed one of the prerequisites for BIO201.

  • Completed BIO201, successful in BIO156 vs successful in BIO156XT – statistically significant difference.  

    Observations: BIO156-BIO201 = 951 vs BIO156XT-BIO201 = 35
    Mean: BIO156-BIO201 = 83% vs BIO156XT-BIO201 91% 
    p(T<=t) one-tail: 0.049

    Even with very limited data (35 observations) for BIO156XT, the differences in averages is substantially higher for BIO156XT (83% vs 91% success).  The hypothesis for this test assumed these averages were the same, the data fails to support this hypothesis.  In other words, the data supports the perception that additional instructional time leads to better student performance (BIO156 to BIO156XT).  These results provide encouragement to consider scheduling future sections for BIO156XT in order to provide further evidence that additional instruction leads to better preparation in BIO156.  Although the data correlates with this opinion, other variables may contribute to this success, including financial status, time of day of the class, full term/short term classes, and various demographics. Correlation does not necessarily represent causation.
     

  • Completed BIO201, successful in BIO156 vs successful in BIO181 – statistically significant difference.  

    Observations: BIO156-BIO201 = 951 vs BIO181-BIO201 = 808
    Mean: BIO156-BIO201 = 83% vs BIO181-BIO201 86% 
    p(T<=t) one-tail: 0.038

    The success rate is higher for BIO81 (83% vs 86% success).  The hypothesis for this test assumed these averages were the same, the data fails to support this hypothesis.  In other words, the data supports the perception that students who succeed in BIO181 perform better in BIO201 than those who succeed in BIO156.  Although the data correlates with this opinion, other variables may contribute to this success, including financial status, time of day of the class, full term/short term classes, and various demographics.  Correlation does not necessarily represent causation.
     
  • Completed BIO201, successful in BIO156 vs successful in BIO181XT– no statistically significant difference.  

    Observations: BIO156-BIO201 = 951 vs BIO181XT-BIO201 = 29
    Mean: BIO156-BIO201 = 83% vs BIO181XT-BIO201 90% 
    p(T<=t) one-tail: 0.136

    The small number of observations (29) in BIO181XT have an adverse effect upon the testing precision.  The success rate (83% vs 90% success) gap is substantial but there is not enough data to meet the 95% confidence interval rigor.  Offering additional BIO181XT sections in the future may be worth consideration to determine if this success gap is statistically significant or not.
     
  • Completed BIO201, successful in BIO156XT vs successful in BIO181– no statistically significant difference.

    Observations: BIO156XT-BIO201 = 35 vs BIO181-BIO201 = 808
    Mean: BIO15XT6-BIO201 = 91% vs BIO181-BIO201 86% 
    p(T<=t) one-tail: 0.146

    The small number of observations (35) in BIO156XT have an adverse effect upon the testing precision.  The success (91% vs 86% success) gap is substantial but there is not enough data to meet the 95% confidence interval rigor.  Offering additional BIO156XT sections in the future may be worth consideration to determine if this success gap is statistically significant or not.
     
  • Completed BIO201, successful in BIO156XT vs successful in BIO181XT– no statistically significant difference.

    Observations: BIO156XT-BIO201 = 35 vs BIO181XT-BIO201 = 29
    Mean: BIO156XT-BIO201 = 91% vs BIO181XT-BIO201 90% 
    p(T<=t) one-tail: 0.407

    The small number of observations (35) in BIO156XT and BIO181XT (29) have an adverse effect upon the testing precision.  The success (91% vs 90% success rate) gap is minimal, there is not enough data to meet the 95% confidence interval rigor.  Offering additional BIO156XT and BIO181XT sections in the future may be worth consideration to determine if this success gap is statistically significant or not.
     
After analyzing, and reflecting on the outcome, what are the next steps?

The data for BIO156XT supports the addition of more BIO156XT sections in the future.  The data for BIO181XT sections was inconclusive, at least partially due to the relatively few observations.  Adding additional sections of BIO181XT will provide more evidence as to the merits of additional class time.

If scheduled, this has impact upon student finances and their class schedules (an additional credit hour for XT classes).  This also may affect faculty and staff and they should have a voice in the decision to add sections with additional instructional time for the same content:

  • The Scheduling department will be adding XT offerings
  • BIO instructor loads need to be reviewed to ensure instructors are not over their allotted load
  • Advisors should be informed as to the higher success in BIO201 for students which took BIO156XT, this should be reiterated when advising our students
  • The Financial Aid department may want to know of this potential change in student advising
     
Abstract

Does additional prerequisite instructional time for the same instructional content have an effect up success in BIO201?  Do one of the four prerequisite options (BIO156 and BIO181 4 credit hours, BIO156XT and BIO181XT 5 credit hours) lead to better success in BIO201?  BIO, in conjunction with OPIE studied the results of student success when completing BIO201 and testing which of the four prerequisite options best prepared students for success.  The results of BIO201 were compared for students who successfully completed one of the four prerequisites.  The results suggest the benefits of further study by scheduling additional 5 credit BIO classes.

Division/Department
Completed Full Cycle
Yes
Course Number
BIO156/156XT/181/181XT/201