Difference Between Frequency and Relative Frequency
Science has evolved so much, and a lot of things have changed as a result. One thing that has remained the same is the fact that nothing is constant. Like the good book will put it; “there is nothing permanent under the sun”, everything is under probability.
Probability expresses the belief that an experiment will turn out in a number of ways. To better describe how this works, we’re going to review the difference between relative frequency and frequency.
This will throw more light on the different number of results that can be gotten from virtually any event at all. But before we go into the difference between frequency and relative frequency, let’s take some time to learn what they really mean.
Definition of Frequency
Frequency is defined as the total amount of times an observation occurred in an experiment or study. For instance, if there are 12 girls and 7 boys in a class, then the frequency of girls is 12, while that of boys is 7. When you talk about how often you bathe in a day or how often you visit someone, you are talking about how frequent you are with those activities.
Despite having the same basic meaning, different fields have different definitions for this term. In physics, for example, it is defined as the number of waves that pass through a fixed point in unit time. In statistics, it is defined as the quantity of times a given datum occurs in a data set.
Here is an example.
- You have a list of results of 20 students in an exam as follows C, A, A, B, B, C, C, D, C, C, C, B, A, A, B, B, C, B, C, and C. In a frequency distribution table, they would be denoted as follows.
| Grades | Frequency |
| A | 4 |
| B | 6 |
| C | 9 |
| D | 1 |
Definition of Relative Frequency
Relative frequency is defined as how often an event takes place divided by all outcomes. It takes into consideration not just the particular events you are interested in but also the rest of the events in the data set. The idea is to compare the events of interest to the total number of events in a given set. This comparison is usually expressed in the form of a fraction, decimal, or percentage.
From this description, we see that when comparing frequency vs relative frequency, the former is concerned with how often an event takes place, while the latter describes how often an event takes place in relation to every event in consideration.
Using the same example above, let us take a look at how to present the relative frequencies of a data set.
- Data set – C, A, A, B, B, C, C, D, C, C, C, B, A, A, B, B, C, B, C, and C
| Grades | Frequency | Relative frequency |
| A | 4 | 4/20 |
| B | 6 | 6/20 |
| C | 9 | 9/20 |
| D | 1 | 1/20 |
While relative frequency vs frequency is somewhat similar in comparison, their difference is literally obvious as shown in the table above. Interestingly, filling out the third column in the table is wholly dependent on the information contained in the second one.
Frequency vs Relative Frequency Comparison Table
| Basis of Comparison | Frequency | Relative Frequency |
| Definition | Simply means the number of times an event occurs within a given experiment | Is the fraction of how many times a result occurs over the total number of tries/entries |
| Calculations | No calculations involved | Calculation is involved in most cases |
| Number form | Simple whole numbers in most cases | Likely to involve fractions in most cases if not all |
Conclusion of the Main Difference Between Frequency vs Relative Frequency
What’s the difference between frequency and relative frequency? The answer to this question, as shown above, is straight forward. This information will help you by the time you get to the next level which requires formulas and actual calculations.
