I work as a lecturer in a university that offers a variety of courses to students. In this University, the admitted students come and pursue either diploma courses, degree courses or post graduate courses. Besides, the university offers a large collection of course choices. This wide collection of courses has led to the establishment of different colleges within the university. Among these colleges are the college of biological and physical sciences, college of humanities and social sciences, college of education and college of health sciences. It is within the college of biological and physical sciences that I work. This college is further divided into two schools: school of biological and school of physical sciences. In particular, I work within the school of biological sciences.
This school brings together students with yet a number of courses related to biological sciences. There are such courses as Bachelor’s degree in biology, microbiology, environmental science, and science. Like in any science course, students doing all these course need to have some understanding of mathematical concepts. This led to the creation of the examinable unit called Biostatistics. The curriculum of the school of biological sciences there requires all the students to do the unit of biostatistics. I teach this unit of Biostatistics. Therefore, I have a big class bringing together the students pursuing degree courses in Biology, Microbiology, Environmental Science and Science (Biology and Chemistry options). It is a big class of around 200 students.
The lesson I am administering at the moment is that on the calculation of standard deviation of grouped data. Before this lesson, the students were exploring the mathematical ideas on the topic of standard deviation for ungrouped data.
1. The goals of the lesson on the standard deviation for grouped data are:
2. to let the students understand the different parts of the standard deviation formula.
3. To let the students know how to obtain these parts from the data provided.
4. To let the students know how to bring together these different parts in the computation of the standard deviation.
Context of the standard deviation for grouped data
I am teaching this lesson segment, a day after I taught standard deviation for ungrouped data. In this case, the computation of the standard deviation for ungrouped data was a bit simpler considering the simplicity of the data used. After this lesson segment, I will teach the students on how to compute variance of grouped data, considering the fact that there is a strong relationship between standard deviation and variance.
In the lesson, I employed the technique of funneling since I wanted to let the students learn from the known to unknown. In the funneling, I asked them a number of questions. These questions were as follows:
1. What is the difference between ungrouped data and grouped data?
2. How can a big sample of data be grouped?
3. How can a frequency table be made from grouped data?
4. How can the midpoint be computed for each class? I told them that this midpoint is designated (X).
5. What is the number of entries seen in each class? I told them to designate this as (f).
6. What is the sum of f values? I told them to designate this as n, representing the total sum of entries in the distribution.
7. What is the mean of the midpoint values? I told them to designate the mean as X-.
8. What is the mathematical symbol for “sum of”?
Where:
SSX=Standard deviation
X=mean
F=frequency
N=total number of f values
Analysis
After ensuring that the students were familiar with all those concepts and parts, I brought the terms together to form the computation formula used for calculating the standard deviation of grouped data. I Realized that the students did not find strange to them since they just saw the different parts they were talking and discussing about being assembled to form the formula. They were in fact very eager to apply the formula.
Conclusion
First, I concluded that it is effective to teach basing on the student’s cognitive skills. This strategy is important since it makes the teacher move at a pace that is comfortable to the students. In other words, once the students demonstrate that they are familiar with a particular concept, the teacher can move on to the next unfamiliar concept. With this pace, the students can easily know what is taking place during any lesson.
Secondly, I learnt that students understand better when they are taken slowly from known concepts to unknown concepts.
Thirdly, I learnt that the process of engaging the students in class using questions is very effective in letting them grasp complex concepts.
