A population is divided into nonoverlapping strata. A random sample is drawn within each stratum, with sample sizes proportional to stratum population sizes. Which sampling method is this?
Stratified Sampling
This is proportionate stratified random sampling. Quota sampling can match category proportions but uses nonprobability selection within quotas. Stratified sampling can also use nonproportional allocation, so proportionality must be specified.
An investigator wants to conduct a study on orthopaedically handicapped children. The type of sampling to be used would be
Match each characteristic in List I with the validity evidence in List II.
List I: (a) Test scores predict later performance on an external criterion; (b) Scores support interpretation in terms of a theoretical psychological construct; (c) Test content represents the intended knowledge domain; (d) Scores relate to an appropriate external criterion measured at about the same time.
List II: (i) Content validity; (ii) Predictive validity; (iii) Concurrent validity; (iv) Construct validity.
The element that differentiates between stratified and quota sampling techniques is
If a sample survey of the same 100 households is conducted in a particular village, annually for five years, the data so collected will be described as :
Assertion A: A concurrent validity coefficient can exceed a predictive validity coefficient when intervening changes weaken the relationship with the later criterion.
Reason R: A higher validity coefficient alone does not establish that a test is more suitable for a particular purpose.