Longitudinal and Cross-Sectional Research
Overview
Use this skill to turn a research target into a two-part deep research report:
- Reconstruct how the subject emerged and evolved over time.
- Compare the subject against the current field, competitors, or substitutes.
Prioritize causal explanation, narrative readability, and source-backed judgment over list-like summaries.
Fit Check
Use this skill when the user wants:
- a deep research report instead of a short answer
- both historical development and current competitive positioning
- analysis of a product, company, organization, technology, concept, or person
- a report that explains why key turning points happened, not just what happened
Do not stop at feature comparison tables. Explain how the subject got here and what that means now.
Workflow
1. Define the target and frame
Start by identifying:
- the exact research target
- the subject type: product, company, person, technology, concept, or organization
- the likely comparison set: direct competitors, close peers, indirect substitutes, or no clear peers
Adjust the comparison dimensions to fit the subject. For example, technical route matters more for protocols than for people, while career arc matters more for people than pricing.
2. Collect source material
Gather sources for both time depth and present-state comparison.
Prefer:
- official docs, company pages, release notes, papers, blogs, filings, and interviews
- reputable reporting and industry analysis
- community evidence for user sentiment when relevant
Always anchor claims with dates when the subject evolved over time. Mark any unverified or inferential statement clearly.
3. Write the longitudinal analysis first
Tell the story from origin to present. Cover:
- origin context: what problem, belief, or market condition gave rise to the subject
- founding or first-publication moment
- major milestones in chronological order
- turning points such as launches, pivots, funding, rewrites, leadership changes, partnerships, acquisitions, controversies, or adoption milestones
- decision logic at each major turning point when it can be inferred from evidence
Do not write a dry timeline. Build a narrative with cause and effect, constraints, and tradeoffs.
4. Choose the cross-sectional mode
Use one of these modes:
- No clear direct competitors: explain why the category is new, narrow, or hard to enter; then analyze likely substitutes and emerging challengers.
- One or two direct competitors: compare each one in depth.
- Three or more competitors: choose the three to five most representative ones and compare the rest briefly if needed.
Compare along dimensions that fit the target, such as:
- technical route or underlying method
- product shape, business model, or operating model
- target users and use cases
- strengths and obvious weaknesses
- pricing, scale, or resource base
- user sentiment and community reputation
- ecosystem position and likely trajectory
5. End with synthesis
Finish with a "Longitudinal-Cross-Sectional Synthesis" section that answers:
- What position does the subject occupy today?
- Which parts of that position come from historical path dependence?
- What opportunities and risks are most visible from the current landscape?
- What future direction is most likely, and which part is inference?
This section should add a fresh judgment, not just compress earlier sections.
Writing Standard
Write like a strong long-form reported analysis, not a management slide deck.
- Make readability the top priority.
- Use human language and concrete details.
- Ground judgment in evidence before interpretation.
- Separate confirmed facts from inference.
- Keep the longitudinal section narrative-driven.
- Keep the cross-sectional section analytical, but still readable and alive.
Output Shape
Default order:
- Longitudinal analysis
- Cross-sectional analysis
- Longitudinal-Cross-Sectional Synthesis
Use tables only as support. The core analysis should stay in prose.
Reference
Read references/method.md when you need the full English prompt template, detailed dimension list, or the original reporting-style constraints.
1---2name: longitudinal-cross-sectional-research3description: Write deep research reports that combine longitudinal history with cross-sectional comparison. Use when asked to analyze a company, product, technology, protocol, organization, market category, or person by tracing origins, milestones, strategy shifts, and then comparing it with current competitors, peers, substitutes, or the surrounding landscape.4---5
6# Longitudinal and Cross-Sectional Research
7
8## Overview
9
10Use this skill to turn a research target into a two-part deep research report:
11
121. Reconstruct how the subject emerged and evolved over time.
132. Compare the subject against the current field, competitors, or substitutes.
14
15Prioritize causal explanation, narrative readability, and source-backed judgment over list-like summaries.
16
17## Fit Check
18
19Use this skill when the user wants:
20
21- a deep research report instead of a short answer
22- both historical development and current competitive positioning
23- analysis of a product, company, organization, technology, concept, or person
24- a report that explains why key turning points happened, not just what happened
25
26Do not stop at feature comparison tables. Explain how the subject got here and what that means now.
27
28## Workflow
29
30### 1. Define the target and frame
31
32Start by identifying:
33
34- the exact research target
35- the subject type: product, company, person, technology, concept, or organization
36- the likely comparison set: direct competitors, close peers, indirect substitutes, or no clear peers
37
38Adjust the comparison dimensions to fit the subject. For example, technical route matters more for protocols than for people, while career arc matters more for people than pricing.
39
40### 2. Collect source material
41
42Gather sources for both time depth and present-state comparison.
43
44Prefer:
45
46- official docs, company pages, release notes, papers, blogs, filings, and interviews
47- reputable reporting and industry analysis
48- community evidence for user sentiment when relevant
49
50Always anchor claims with dates when the subject evolved over time. Mark any unverified or inferential statement clearly.
51
52### 3. Write the longitudinal analysis first
53
54Tell the story from origin to present. Cover:
55
56- origin context: what problem, belief, or market condition gave rise to the subject
57- founding or first-publication moment
58- major milestones in chronological order
59- turning points such as launches, pivots, funding, rewrites, leadership changes, partnerships, acquisitions, controversies, or adoption milestones
60- decision logic at each major turning point when it can be inferred from evidence
61
62Do not write a dry timeline. Build a narrative with cause and effect, constraints, and tradeoffs.
63
64### 4. Choose the cross-sectional mode
65
66Use one of these modes:
67
68- No clear direct competitors: explain why the category is new, narrow, or hard to enter; then analyze likely substitutes and emerging challengers.
69- One or two direct competitors: compare each one in depth.
70- Three or more competitors: choose the three to five most representative ones and compare the rest briefly if needed.
71
72Compare along dimensions that fit the target, such as:
73
74- technical route or underlying method
75- product shape, business model, or operating model
76- target users and use cases
77- strengths and obvious weaknesses
78- pricing, scale, or resource base
79- user sentiment and community reputation
80- ecosystem position and likely trajectory
81
82### 5. End with synthesis
83
84Finish with a "Longitudinal-Cross-Sectional Synthesis" section that answers:
85
86- What position does the subject occupy today?
87- Which parts of that position come from historical path dependence?
88- What opportunities and risks are most visible from the current landscape?
89- What future direction is most likely, and which part is inference?
90
91This section should add a fresh judgment, not just compress earlier sections.
92
93## Writing Standard
94
95Write like a strong long-form reported analysis, not a management slide deck.
96
97- Make readability the top priority.
98- Use human language and concrete details.
99- Ground judgment in evidence before interpretation.
100- Separate confirmed facts from inference.
101- Keep the longitudinal section narrative-driven.
102- Keep the cross-sectional section analytical, but still readable and alive.
103
104## Output Shape
105
106Default order:
107
1081. Longitudinal analysis
1092. Cross-sectional analysis
1103. Longitudinal-Cross-Sectional Synthesis
111
112Use tables only as support. The core analysis should stay in prose.
113
114## Reference
115
116Read [references/method.md](references/method.md) when you need the full English prompt template, detailed dimension list, or the original reporting-style constraints.
hexbee