Question 1

What is the difference between a signal detection and identification (absolute judgement) task?

Accepted Answer

Identification tasks typically involve distinguishing among several stimulus states or categories, whereas signal detection tasks often focus on discerning the presence or absence of a signal, thus generally involving a simpler, two-choice scenario.

Question 2

When is signal detection theory (SDT) applicable?

Accepted Answer

Signal detection theory is applicable when there are two discrete states of the world, typically referred to as signal (the presence of what is being detected) and noise (the absence of the signal or presence of something else).

Question 3

Which of the following is not one of the classes of joint events in signal detection theory (SDT)?

Accepted Answer

In signal detection theory (SDT), the classes of joint events include hits (correctly detecting a signal when it is present), false alarms (incorrectly detecting a signal when it is not present), and correct rejections (correctly identifying that no signal is present). "False miss" is not a standard term used in SDT; instead, the term "miss" is used to describe failing to detect a signal when it is present.

Question 4

The quantification of information is influenced by three variables. Which of the following is NOT one of them?

Accepted Answer

Redundancy is not a direct variable in the quantification of information; it refers to the repetition or predictability within a message, which can affect the efficiency of information transmission but is not a primary factor in quantifying information itself.

Question 5

If 20 signal trials and 10 noise trials were presented and there were 2 hits and 18 misses, which of the following is the correct hit rate?

Accepted Answer

The hit rate is calculated by dividing the number of hits by the total number of signal trials, which is 2 hits out of 20 signal trials, resulting in 2/20 = .1.

Question 6

Can the value of evidence variable X ever exceed the criterion X_C?

Accepted Answer

The notation X_C seems to be a specific criterion or threshold value related to signal detection theory or a similar context. The value of an evidence variable X can exceed this criterion when either signal or noise is presented, as the evidence variable X represents the observer's perception or measurement, which can vary based on the presence of signal, noise, or both.

Question 7

In SDT we represent signal and noise as a pair of distributions. Which of the following is a true statement concerning these distributions:

Accepted Answer

In Signal Detection Theory (SDT), it is assumed that both signal and noise are represented by normal (Gaussian) distributions and there is always some overlap between these distributions, reflecting the uncertainty or difficulty in distinguishing signal from noise in many detection tasks.

Question 8

In SDT we represent signal and noise as a pair of distributions. Which of the following describes conservative responding?

Accepted Answer

Conservative responding in Signal Detection Theory (SDT) refers to a bias where the observer prefers to say "no" (signal absent) more often than "yes" (signal present), erring on the side of caution and requiring a higher level of evidence before identifying a signal as present. This is opposed to a liberal bias, where the observer is more likely to say "yes" (signal present).

Question 9

The ______ the difference between signals and noise, the greater these error probabilities become because the amount of variation in X resulting from randomness increases relative to the amount of energy in the signal.

Accepted Answer

The smaller the difference between signals and noise, the harder it is to distinguish the signal from the noise, leading to higher error probabilities.

Question 10

Which of the following defines β_opt in response to changes in signal probability?

Accepted Answer

The answer of Which of the following defines β_opt in...

Question 11

Optimal beta can be defined in terms of payoffs (costs and values). Which of the following should increase optimal beta?

Accepted Answer

The answer of Optimal beta can be defined in terms...

Question 12

Sluggish beta refers to:

Accepted Answer

Sluggish beta refers to the phenomenon where, as the optimal beta is adjusted due to changes in probabilities or payoffs, the empirical beta values do not shift as much as they theoretically should. This results in a smaller change in empirical beta values than necessary, indicating a sluggish response to new information or changes in the market environment.

Question 13

Which of the following statements about sluggish beta is false?

Accepted Answer

Sluggish beta is not just a laboratory phenomenon; it can also occur in real-world decision-making scenarios.

Question 14

A key contribution of signal detection theory is that it:

Accepted Answer

Signal detection theory makes a clear distinction between an observer's sensitivity to the presence of a stimulus and their response bias, which is their tendency to report detecting a stimulus under conditions of uncertainty. This allows for a more nuanced understanding of perception and decision-making processes.

Question 15

A Receiver Operating Characteristic (ROC) curve plots:

Accepted Answer

A Receiver Operating Characteristic (ROC) curve plots the true positive rate (hits) against the false positive rate (false alarms) for different threshold settings.

Question 16

How many points on the ROC can be generated from a 2 x 2 response matrix?

Accepted Answer

The answer of How many points on the ROC can...

Question 17

Points along a single ROC curve have the same:

Accepted Answer

The answer of Points along a single ROC curve have...

Question 18

Confidence levels is a:

Accepted Answer

Confidence levels are used in signal detection theory as a method to adjust the criterion for making decisions under uncertainty, aiming to optimize decision-making by balancing misses and false alarms. This helps in setting an optimal level for decision criteria, improving the decision-making process in uncertain conditions.

Question 19

A point on the positive diagonal on an ROC curve indicates which of the following:

Accepted Answer

A point on the positive diagonal of an ROC (Receiver Operating Characteristic) curve represents a situation where the true positive rate equals the false positive rate, indicating that the model's predictions are no better than random chance. This is referred to as chance responding or zero sensitivity, as the model does not effectively discriminate between the classes more accurately than flipping a coin would.

Question 20

What happens when an ROC curve is plotted using z-scores?

Accepted Answer

Using z-scores does not change the fundamental shape of the ROC curve; it remains a curve. However, plotting with z-scores can standardize the scale, making it easier to interpret, but it does not alter the curve into a straight line or affect its steepness inherently. The ROC curve's shape is determined by the true positive rate vs. the false positive rate at various threshold settings, not the scale of the scores used.

Quiz 2: Signal Detection and Absolute Judgement

What is the difference between a signal detection and identification (absolute judgement) task?

When is signal detection theory (SDT) applicable?

Which of the following is not one of the classes of joint events in signal detection theory (SDT) ?

The quantification of information is influenced by three variables. Which of the following is NOT one of them?

If 20 signal trials and 10 noise trials were presented and there were 2 hits and 18 misses, which of the following is the correct hit rate?

Can the value of evidence variable X ever exceed the criterion X_C?

In SDT we represent signal and noise as a pair of distributions. Which of the following is a true statement concerning these distributions:

In SDT we represent signal and noise as a pair of distributions. Which of the following describes conservative responding?

The ______ the difference between signals and noise, the greater these error probabilities become because the amount of variation in X resulting from randomness increases relative to the amount of energy in the signal.

Which of the following defines β_opt in response to changes in signal probability?

Optimal beta can be defined in terms of payoffs (costs and values) . Which of the following should increase optimal beta?

Sluggish beta refers to:

Which of the following statements about sluggish beta is false?

A key contribution of signal detection theory is that it:

A Receiver Operating Characteristic (ROC) curve plots:

How many points on the ROC can be generated from a 2 x 2 response matrix?

Points along a single ROC curve have the same:

Confidence levels is a:

A point on the positive diagonal on an ROC curve indicates which of the following:

What happens when an ROC curve is plotted using z-scores?

Quiz 2: Signal Detection and Absolute Judgement

What is the difference between a signal detection and identification (absolute judgement) task?

When is signal detection theory (SDT) applicable?

Which of the following is not one of the classes of joint events in signal detection theory (SDT) ?

The quantification of information is influenced by three variables. Which of the following is NOT one of them?

If 20 signal trials and 10 noise trials were presented and there were 2 hits and 18 misses, which of the following is the correct hit rate?

Can the value of evidence variable X ever exceed the criterion XC?

In SDT we represent signal and noise as a pair of distributions. Which of the following is a true statement concerning these distributions:

In SDT we represent signal and noise as a pair of distributions. Which of the following describes conservative responding?

The ______ the difference between signals and noise, the greater these error probabilities become because the amount of variation in X resulting from randomness increases relative to the amount of energy in the signal.

Which of the following defines βopt in response to changes in signal probability?

Optimal beta can be defined in terms of payoffs (costs and values) . Which of the following should increase optimal beta?

Sluggish beta refers to:

Which of the following statements about sluggish beta is false?

A key contribution of signal detection theory is that it:

A Receiver Operating Characteristic (ROC) curve plots:

How many points on the ROC can be generated from a 2 x 2 response matrix?

Points along a single ROC curve have the same:

Confidence levels is a:

A point on the positive diagonal on an ROC curve indicates which of the following:

What happens when an ROC curve is plotted using z-scores?

Can the value of evidence variable X ever exceed the criterion X_C?

Which of the following defines β_opt in response to changes in signal probability?