Can a school survey replace it?

A survey gives status. It cannot give a true velocity curve for each child.

Why not X-ray every visit?

Radiation and consent limit skeletal-age films. Height remains the workhorse.

Q5(c) · UPSC Civil Services Mains 2015 · Anthropology GS 1 · 10 marks · 1 min read

← Q7(a)

Longitudinal method of studying growth.

Topic: Distinction between technique, method and methodology. Syllabus: (b) Distinction between technique, method and methodology Same official PYQ from year-wise 2015 and Distinction between technique, method and methodology.

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Longitudinal method repeats measures on the same children. It reveals tempo and peak height velocity. Tanner’s Harpenden study is the classic. Cross-sections are cheaper but mix early and late maturers. Dropout and secular change are the main limits.

Model answer

Copper italics in this answer — like this — are the key facts. Each one is unpacked in the Facts & figures rail.

Introduction

A longitudinal growth study measures the same children again and again. It is the method that can see tempo, not only size.

Body

How it works

Height, weight, and skeletal age are taken at fixed intervals on one cohort.
Tanner at Harpenden showed spurts, peak height velocity, and individual tempo that a one-time survey misses.
Indian series, such as work associated with ICMR and university auxology units, used mixed-longitudinal designs when pure follow-up was costly.

Contrast and limit

Cross-sectional studies are cheaper and map a population at one date. They smear early and late maturers together.
Longitudinal work suffers dropout, secular change during the study, and ethics of repeated X-rays.
The method is gold for velocity curves; it is poor as a quick census.

Flow diagram

flowchart TD
  L[Longitudinal] --> S[Same child over time]
  S --> V[Velocity spurt]
  C[Cross-section] --> Z[Size at one date]

Conclusion

Longitudinal growth study follows persons through time. Tanner-style velocity is its yield; cost and attrition are its price.

Quick related

Students also ask

Can a school survey replace it?

A survey gives status. It cannot give a true velocity curve for each child.
Why not X-ray every visit?

Radiation and consent limit skeletal-age films. Height remains the workhorse.

Same topic · past papers

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These previous-year questions sit on the same topic. Open one to practise the earlier ask.

2023 · Q3(c) · Anthropology GS 1 · 15 marks
What is mixed-longitudinal method of studying human growth. Discuss its merits and demerits.
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