Friday, August 7, 2009

Qualities of a Good Lecturer

What is the difference between a Teacher and Lecturer?A teacher is any one who teaches students.
Lecturing means giving a lecture or talk in front of an audience.
A teacher may give lectures to his/her students. So essentially lecturing is one of the methods of teaching.
Usually for degree courses, the teachers are called lecturers, since they are supposed to give informative talk to students.
Who is a good Lecturer?


  1. Lecturer should be able to generate interest in the subject. Lecturing is an art, a skill, by which the speaker should be able to generate interest among the students on the subject. We have come across many lecturers, who in their first talk itself, tells the students that this is a boring subject and you need to study byheart these modules to pass the examination. Most of the students interest will be gone by this single comment.

  2. Lecturer need to introduce the importance of the subject, why it is needed and what the student is expected to know once he master the subject. Most the lecturers directly start lecturing about the topics given in the syllabus. Even after completion of the course student may not know what this subject was and why he studied it.

  3. Lecturer need to ensure that atleast the fundamentals about the subject are conveyed to the students in the most simplest and interesting manner possible. Unless the fundamentals are set straight, creating interest for the subject is impossible. Also if the fundamentals are repeated in different styles it will stay put in the mind of students which is sure to help him in future.

  4. Lecturer need not give lecture notes and cover the syllabus fully. Most of the students like lectures who give notes corresponding to each of the contents in the syllabus. In such cases, students will just byheart the contents given in notes and write the exams. Here the retention power of the students are made use of. The subject fundamentals are never conveyed to the student. This scenario is as good as not studying the subject at all.

  5. Lecturer should always encourage students to do more research on the subject. To encourage research aptitute, the best tool is assignments. But what is happening now in the name of assignments.When ever students are given assignments, Lecturer gives one particular portion of the syllabus and ask the student to write notes about it. Most of the times this portion will be the one which the lecturer don't want to lecture about in the class. The student simply refers some textbook, copy whatever is given there and submit it. Result is that the student will have no idea on what he has written.The lecturer should not simply give a topic for assignment. He should introduce the topic and try to give some practical problem, whose solution should be arrived at by the students after understanding the concepts of the subject. Then atleast some of the students will try to apply the knowledge of the subject and find solution to the problem posed at them as assignments.

  6. Lecturer should have a passion for teaching. This is the foremost thing. Only very few people land in a lecturer job out of their own interest. Rest of them are joining just because they could not find any other career. But whatever it may be, unless one a has passion for his job, he will not be able to deliver the goods.

Wednesday, August 5, 2009

Integration - Demystified

Integration is something closely associated with differentiation (click here to know what is differentiation). We all have studied lots of standard integrals, but do we know the answer to following questions.
What is integration?
Why is integration needed?

What are some practical examples of integration?
If you know the answer then you need not read this post, if you don't know the answer reading this is sure to help you.

What is integration?
The process of finding the value of an integral is called integration.
Well am I supposed to repeat this standard definition. No, let us try to understand it in a different manner.
Consider the following graph.

A rectangle is shown inside a graph whose properties are as given below
Length = 5Breadth = 4
Area of this rectangle = 5 x 4 = 20.
Let me explain this rectangle little elaborately. The length of the rectangle is shown along the X axis. For all the values of X, the value of Y is a constant. ie when X varies from 0 to 5, the value of Y is 4. Hence we could calculate the area by simply multiplying.
If the value of Y was changing then the figure won't be a rectangle.
Consider the figure given below

Is this a rectangle? No..
Why? The value of Y is not a constant. As X is varying the value of Y is varying as shown below
X = 1, Y = 4
X = 2, Y = 3
X = 3, Y = 2
X = 4, Y = 1
Now how can we calculate the area of this shape. We are trying to find out the area of the shaded region.
If the figure is broken down as shown below we can find the area

Each of the above figure is a rectangle. So the area of the total shape is the area of each of the shapes given above. Since each of the above figure is a rectangle calculating area of each of the shapes is simple.
Area = (L1 x B1) + (L2 x B2) + (L3 x B3) + (L4 x B4)
Area = 1 x 4 + 2 x 3 + 3 x 2 + 4 x 1 = 20
Now we can analyse how we found the area of this irregular shape.
For each value of X we found that the value of Y is remaining a constant. Hence we were able to calculate the area for each value of X and then finally add up the results together and find the total area
If you understood the above statement, you understood what is integration.

Integration is the technique used to find the area under any shape.

How to find the area under any shape?
Just like the way we found out the area of the last shape. For each value of X where Y is a constant, find the area and then sum up the values. Here we used the principle of integration to find out the area.

Now we can explain these things in a more mathematical terminology.
If a variable "y" is changing as the value of "x" is increasing in a particular pattern, then we say that y is a function of xie y = f(x)
So the shapes which we showed above also can be written as y = f(x)
To calculate the integral of y,
means to calculate the integral of f(x)
means to find out the area under the curve when 'x' varies from 1 to 4 and 'y' varies from 1 to 4
The steps are
1. Divide the total shape in small intervals of X. This small interval of X is called "dx".
2. Find out the area. Area = breadth x length, here breadth = y, (value of y at that point), hence area = y. dx
3. Take the sum of all areas corresponding to each dx.the symbol for integral is an elongated "S" which represents sum

So integration is a method for finding the area under a curve, where the equation of the curve is given by y = f(x)

Why do we need to study the standard integration of various functions?
In the last example we calculated the area of a figure when the value of x was varying from 1 to 4. Also the value of y contianed 4 different values. Hence manual computation was possible.
If there were X was needed to be divided into 1000 values, then we have to find the area of 1000 different shapes and then find the sum. Will it be possible to manually compute this.
So what will we do?
The curve can be represented as y = f(x), where f(x) may be some standard function.
So if the integral of the standard function is known we can compute the area very simply.
Consider the function y = x
Here if we are asked to find out the integral of y, when x varies from 0 to 4, we can manually calculate like the following
the function is y = x.
hence when
x = 0, y = 0
x = 1, y = 1
x = 2, y = 2
x = 3, y = 3
x = 4, y = 4
The figure can be drawn as shown below.

To manually compute the area, we can find out the number of squares in the shaded region,
there are 6 squares and 4 half squares
each square's area is 1.
hence the total area is 6 + 2 = 8.
If we use integration
Using integration also we got the same result.

If we need to find the integral of y = x, when x varies from 0 to 100, can we do it manually?
It is quite tedious, to count the number of squares like we did earlier.
But if we use the integration equation then we can compute as follows

Whatever complex the curve is, if we can express it as a function of x, then to find the area we need to compute the expression after integration, then substitute the limit values to get the result.

What is the practical application of Integration?
This can be used to find the area of a plane what ever be its shapeExtending the principle this can be used to find the volume of a 3D shape.Finding area and volume has n number of practical applications.
Hope you understood the concepts. Now plunge into one of those text books and get more detail. It will become more interesting :)