Introduction To Research - Test 1

Explanation
Validity of a screening test means getting the correct results while reliability of the screening test means getting the same results every time.

Explanation
Sensitivity and specificity are statistical measures used to evaluate the performance of a diagnostic test. Sensitivity measures the proportion of true positives correctly identified by the test, while specificity measures the proportion of true negatives correctly identified by the test. These two measures have an inverse relationship because as sensitivity increases, specificity tends to decrease, and vice versa. This is because there is often a trade-off between correctly identifying true positives and true negatives. Therefore, it is true that sensitivity and specificity have an inverse relationship.

Explanation
Use Bayes' rule, and solve for P(D)

Explanation
Find the probability of the false positive test results.

Explanation
Find the positive predictive value (PPV)

Explanation
Parameter and statistic are types of statistical measures. In statistics, a parameter is a numerical value that describes a population, while a statistic is a numerical value that describes a sample. Both parameters and statistics are used to summarize and analyze data in order to make inferences about a population. They are important tools in statistical analysis and help researchers draw conclusions and make predictions based on data collected.

Explanation
This the definition of inferential statistics.
Descriptive statistics only organizes and summerizes data.

Explanation
This statement is true because measurements involve the process of observing and quantifying a physical quantity or attribute. Whether it is measuring the length of an object, the temperature of a room, or the weight of an item, all measurements require observation. Thus, it can be concluded that all kinds of measurements are observations.

Explanation
Ethical issues regarding confidentiality may arise in the method of observing. When researchers observe individuals or groups without their knowledge or consent, it can infringe upon their privacy and confidentiality. Observing people without their permission can lead to the disclosure of sensitive information or behaviors that they may not want to be made public. Therefore, it is important for researchers to obtain informed consent and ensure that the privacy and confidentiality of the participants are protected when using the method of observation.

Explanation
Multistage sampling does not necessarily have a low cost. In fact, it can sometimes be more expensive than other sampling methods due to the need to sample at multiple stages or levels. The cost of multistage sampling can depend on factors such as the number of stages, the size of each stage, and the complexity of the sampling design. Therefore, the statement that multistage sampling has a low cost is not correct.