While wandering in jungle, King Dushyant married Shankuntala as narrated in the "Abhigyan Shankuntalam". He gave her royal ring which could serve her identity when she would come to meet him, in future. However, she had lost the ring while going to meet him. When she arrived at Dushyant's palace, he failed to recognise her as she did not had the ring. Which of the following statistical error King Dushyant had committed in this narrative?
Type I errors
This question asks us to identify the type of statistical error King Dushyant committed based on the narrative from "Abhigyan Shankuntalam". The core issue is King Dushyant's failure to recognize Shakuntala because she lacked the royal ring, which was the expected proof of her identity as his wife.
In statistics, particularly in hypothesis testing, we make decisions based on data. There's always a possibility of making an incorrect decision. These incorrect decisions are classified into two main types of errors:
Let's look at the possible outcomes of a hypothesis test:
| Actual Situation | Decision based on test | Outcome |
|---|---|---|
| $H_0$ is True | Fail to Reject $H_0$ | Correct Decision |
| $H_0$ is True | Reject $H_0$ | Type I Error |
| $H_0$ is False | Fail to Reject $H_0$ | Type II Error |
| $H_0$ is False | Reject $H_0$ | Correct Decision |
Let's frame the situation in the narrative in terms of hypothesis testing:
King Dushyant used the presence of the royal ring as his test or criterion. His decision rule was essentially:
Now, let's consider the reality and the King's decision:
Comparing the Actual Situation ($H_0$ is True) with the Decision (Reject $H_0$), we see that the King rejected a true null hypothesis.
This matches the definition of a Type I error.
If it had been a Type II error, it would mean Shakuntala was *not* his wife ($H_0$ is false), but he incorrectly recognized her anyway (failed to reject $H_0$). That is not what happened in the story.
In the narrative, King Dushyant's condition for recognition was the presence of the royal ring. When the ring was absent, he concluded she was not his wife, despite the fact that she truly was. Rejecting the true null hypothesis (that she is his wife) because the evidence (the ring) was missing constitutes a Type I error.
| Error Type | Description | Analogy in Narrative |
|---|---|---|
| Type I Error ($\alpha$) | Rejecting a true $H_0$ (False Positive) | Rejecting that Shakuntala is wife ($H_0$ True) |
| Type II Error ($\beta$) | Failing to reject a false $H_0$ (False Negative) | Failing to reject that Shakuntala is wife ($H_0$ False) - Not the case here. |
Hypothesis testing is a fundamental concept in statistics used to make inferences about a population based on sample data. It involves setting up two competing hypotheses:
The process involves collecting data, performing a statistical test, and calculating a p-value. The p-value is the probability of observing data as extreme as, or more extreme than, the sample data, assuming the null hypothesis is true. Based on the p-value and a chosen significance level ($\alpha$), we decide whether to reject or fail to reject the null hypothesis.
The significance level ($\alpha$) is the maximum acceptable probability of committing a Type I error. Common values for $\alpha$ are 0.05 (5%) or 0.01 (1%). There is a trade-off between Type I and Type II errors; reducing the probability of one type of error often increases the probability of the other, for a fixed sample size.
Given below are two statements
Statement I: The qualitative data are powerful because they are collected from very sensitive social, historical and temporal context.
Statement II: Context sensitivity cannot be completely removed from the qualitative data.
In light of the above statements, choose the correct answer from the options given below
Given below is a summary of ANOVA for four groups of students tested in a research project:
| Source of variance | SS (Sum of squares) | df (Degree of freedom) | MS (Mean sum of squares) |
| Between groups | 76 | 3 | 23.33 |
| Within groups | 122 | 16 | 7.62 |
What will be the value of 'F' for the above data?
An investigator used ANOVA to compare four groups of students on numerical ability on the basis of a test. After analysis of raw scores, the following results were obtained:
| Source of variation | df | Sum of Squares |
| Between Groups | 3 | 625.00 |
| Within Groups | 36 | 2128.00 |
The value of F-ratio would be approximate:
In randomly constituted two groups-experimental and control, a researcher obtains the following results after using a parametric 't' test:
Value of t = 3 for N = 300
On the basis of this evidence which decision in respect of substantive research hypothesis and the null hypothesis will be justified?
Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R). Read the statements and choose the correct answer using the code given below.
Assertion (A): Homogenous tests have low reliability.
Reason (R): The range of test scores affects reliability.