Level 5 — Advanced · Technical & Evidence-Based Writing
Task 57: Defining and Classifying a Concept
Build a category tree with one consistent criterion instead of a vague mixed list — the writing side of the definition-and-classification reading strategy Lesson 57 taught.
Learning Objectives
By the end of this task, you should be able to:
- State a clear definition before classifying, using a recognised definition signal phrase
- Divide a concept into categories using a single, explicitly named criterion
- Avoid mixing two different criteria inside the same classification
Introduction
Lesson 57 taught you to read a classification for its criterion — the one rule an author used to split a concept into categories — and to catch it when two different rules get mixed together by mistake. Writing a classification well means doing that discipline yourself: picking one criterion, naming it, and building categories that genuinely follow from it.
The Rule, for Writing
Core Concept
A weak classification lists types without a rule: "Systems are manual, automated, or expensive." A strong one states a definition first, names its single classification criterion, and divides into categories that actually follow that one criterion — never mixing, say, a cost-based category into an automation-based split.
Example
Port billing systems can be classified according to their level of automation. Manual systems require staff to calculate and enter every charge by hand. Semi-automated systems calculate standard charges automatically but still require staff review for unusual cargo. Fully automated systems calculate and issue charges without human intervention, except when a rule-based exception is flagged for review.
Your Turn
Your Turn
Choose a concept you know well (a type of software, a role, a process, a product category) and write a short classification of it. Open with a definition using a signal phrase (is defined as, refers to, consists of). State one explicit classification criterion, then divide the concept into two or three categories that follow strictly from that single criterion, with one concrete example for each category.
Vocabulary in Context
criterionnounformal
the single rule or standard a classification is built on (মানদণ্ড)
Often with classification criterion, meet the criterion, single criterion
“The criterion for the classification is vessel size.”
mutually exclusivephrasetechnical
categories that don't overlap, so nothing belongs to more than one at once (পরস্পর বর্জনশীল)
Often with mutually exclusive categories, are mutually exclusive, not mutually exclusive
“The categories must be mutually exclusive so that no incident is counted twice.”
falls intophrasal verbneutral
belongs to a particular category within a classification (এই শ্রেণিভুক্ত হয়)
Often with falls into a category, falls into two groups, falls into the category of
“Each incident falls into exactly one category.”
Model Answer
Show a model answer
Customer support tickets can be classified according to how they are resolved. Self-resolved tickets are closed by the customer using a help article or automated chatbot, without any staff involvement. Agent-resolved tickets require a support agent to respond directly, usually because the issue is account-specific or the automated options failed to answer it. Escalated tickets are passed from a frontline agent to a specialist team, typically because the issue involves a technical bug or a billing dispute beyond the frontline agent's authority to resolve. This resolution-based criterion is separate from ticket priority or channel, and mixing either of those in would break the classification's single, consistent rule.
Self-Check
Self-Check
- Did you open with a clear definition, signaled by a phrase like "is defined as" or "refers to"?
- Did you name one explicit classification criterion?
- Do all your categories follow that single criterion, without a second rule sneaking in?
- Did you give at least one concrete example per category?
Next: Writing 58 — Explaining a Mechanism: showing not just what happens, but exactly how a cause produces its effect.