UPHESC Assistant Professor Psychology 2025 PYQs

Concept: Lengthening a test raises reliability only if the added items are parallel/homogeneous to the existing ones.

1. Spearman–Brown: $r_{nn}=\frac{n{r}_{11}}{1+(n-1)r_{11}}$ – assumes added items are equivalent.
2. Adding poor or heterogeneous items can lower reliability.
3. Gains also level off, and fatigue/boredom in very long tests reduces it.

Short trick: Longer = more reliable – only with comparable items.

Concept: Test-retest reliability is the similarity (correlation) of the same people's scores on the same test given twice across a given time interval – the coefficient of stability.

1. Similarity of scores is a matter of reliability, so the 'validity' options are out.
2. Split-half compares two halves of a single administration (internal consistency), not scores across time.
3. Correlating the two sets of scores over the time gap gives the stability coefficient.

Short trick: Same test + same people + time gap = test-retest (stability).

Concept: Performance tests require the manipulation of objects (blocks, form boards, pictures) and use no language in responding.

1. Examples: Kohs' Block Design, Alexander's Passalong, Koh's, Bhatia Battery, Seguin Form Board.
2. Useful for illiterates, young children, deaf or linguistically different groups.
3. Verbal tests need reading/writing/speaking.

Short trick: No words, only doing = Performance test.

Concept: The correlation between two halves is the reliability of a half-length test; the Spearman–Brown formula steps it up to full length.

1. $r_{tt}=\frac{2r_{hh}}{1+r_{hh}}$; e.g., $r_{hh}=0.60$ gives $r_{tt}=0.75$.
2. Product-moment r gives only the half-test correlation.
3. Alpha and KR-20 are separate internal-consistency coefficients, not corrections.

Short trick: Split-half → Spearman–Brown 'prophecy' formula.

Concept: Anastasi distinguishes developmental norms from within-group norms.

1. Within-group norms compare a person with the standardisation group of his own kind: percentiles, standard scores (z, T, stanine), deviation IQ.
2. Developmental norms show how far along a developmental path a person is: mental age, grade equivalents, ordinal scales.
3. So grade equivalents are developmental, not within-group.

Short trick: Age/grade equivalents = developmental; percentiles/z/deviation IQ = within-group.

Concept: A standardised test must be valid, because a test is useless if it does not measure what it claims to measure.

1. (A) True: validity (with reliability and norms) is an essential requirement of a standard test.
2. (R) True: this is the classic definition of validity.
3. Because validity guarantees the test measures its intended trait, it is a prerequisite – R explains A.

Short trick: Valid = measures what it claims → must for every standard test.

Concept: Welch's F-test is a robust one-way ANOVA that does not assume equal variances and works well with unequal group sizes.

1. Ordinary F is distorted when variances differ, especially with unequal n.
2. Welch weights groups by $n/s^2$ and adjusts the error df.
3. Roy–Bargmann step-down F is a MANOVA follow-up for multiple DVs; many t-tests inflate Type I error.

Short trick: Unequal variances: 2 groups → Welch's t; 3+ groups → Welch's F.

Concept: The normal curve is perfectly symmetrical and unimodal, so mean = median = mode at the centre.

1. Skewness = 0, kurtosis mesokurtic (β₂ = 3).
2. In positive skew: mean > median > mode; in negative skew: mean < median < mode.
3. ≈68.26% of cases lie within ±1σ, 95.44% within ±2σ, 99.73% within ±3σ.

Short trick: NPC: three M's meet at the middle.

Concept: In Piaget's sensorimotor stage (0–2 years) infants learn through actions and senses; repeating an action to get an interesting effect is a secondary circular reaction (4–8 months).

1. Shaking a rattle to hear the noise = action → interesting result → repeated.
2. This is substage 3 (secondary circular reactions) of the sensorimotor period.
3. Pre-operational (2–7) involves symbolic play and language; concrete (7–11) logic on concrete objects; formal (11+) abstract reasoning.

Short trick: Rattle-shaking baby = Sensorimotor (0–2 yrs).

Concept: La belle indifference – a surprising lack of concern about one's own serious-looking symptom – is classically linked with conversion disorder (functional neurological symptom disorder).

1. Conversion: loss of motor/sensory function (paralysis, blindness) without organic cause, linked to psychological conflict.
2. The patient seems calm or indifferent about the disability.
3. In somatic symptom disorder, by contrast, the person is excessively worried about symptoms.

Short trick: 'Beautiful indifference' to paralysis = Conversion (old 'hysteria').