DET Interactive Writing: Add Evidence Instead of Repeating

First response: “Universities should lend laptops because reliable devices improve access to coursework.”

Follow-up: “What practical challenge might this policy create?”

Weak continuation: “In other words, universities should provide laptops so students can access coursework.”

The wording changes, but the informational value does not. The follow-up asks for a challenge; the response paraphrases the original benefit.

This guide focuses on adding one new unit of development in current Duolingo English Test Interactive Writing: a reason, example, mechanism, or qualification that answers the customized follow-up. For concession and stance vocabulary, use DET Interactive Writing: answering the follow-up question.

Duolingo’s official description says Interactive Writing begins with a response and then presents a follow-up on the same subject, allowing you to develop the original writing further. Development is not synonymous with length. Use the DET vocabulary practice hub and Exam English hub for related work. The prompts and responses below are original.

The new-information test

After each follow-up sentence, ask:

What can the reader understand now that was not available in my first response?

If the answer is “the same claim in different words,” you have reformulated rather than developed.

Compare:

First: “Flexible schedules can reduce commuting pressure.”

Repeat: “Put differently, flexible hours make commuting less difficult.”

Development: “For example, allowing employees to start between seven and ten spreads arrivals beyond the most crowded hour.”

The example introduces an operational detail and shows how the claimed benefit could occur.

Reformulation can clarify a difficult sentence, but it should not consume the follow-up when the question requests new content.

Four ways to add value

1. Add a new reason

A reason supplies another basis for the position.

First claim:

“Cities should maintain public drinking fountains because they reduce reliance on disposable bottles.”

New reason:

“They also give people who cannot afford frequent purchases reliable access to water in public spaces.”

The second reason concerns access rather than waste. Do not present one reason twice with synonyms: “less plastic” and “fewer plastic bottles” are probably the same reason.

2. Add a concrete example

An example instantiates the claim in a specific, relevant situation.

“A commuter whose train is delayed could refill a bottle at the station instead of buying another drink.”

A useful example contains enough detail to show the claim working. It does not need an invented statistic, named institution, or personal story presented as fact.

3. Explain a mechanism

A mechanism shows the steps connecting an action to an outcome.

Claim:

“Shared digital calendars can reduce missed deadlines.”

Mechanism:

“When one person changes a due date, the update becomes visible to the whole group, so members do not continue working from separate outdated lists.”

The mechanism answers how. Merely saying “calendars are efficient” renames the benefit without explaining it.

4. Add a qualification

A qualification narrows the conditions under which a claim holds.

“The system would help only if every team member can access it and someone is responsible for keeping dates current.”

This does not abandon the original position. It states the conditions needed for the mechanism to work.

Match the development move to the question

Follow-up wording usually signals the missing work:

• “What is another benefit?” → add a distinct reason or result.
• “Can you give an example?” → instantiate the claim.
• “Why would this happen?” or “How would it work?” → explain a mechanism.
• “What problem might arise?” → add a limitation or counterexample.
• “Under what conditions?” → qualify scope.
• “Who might disagree, and why?” → represent another perspective with a reason.

Do not force a favorite paragraph shape onto every prompt. Answer the requested relationship first.

Worked response pair

Initial prompt: Should public libraries lend tools and household equipment as well as books?

First response:

“Public libraries should offer a small equipment-lending collection. Many people need a drill, sewing machine, or measuring device only occasionally, so individual ownership can be expensive and wasteful. A shared collection would let residents complete short projects without purchasing items that remain unused most of the year. Libraries already manage loans and reservations, making them a reasonable place to test the service. However, the collection should begin with durable items that staff can inspect safely.”

Follow-up: What is one operational difficulty, and how could the library address it?

Weak follow-up:

“Libraries should lend equipment because people do not use every tool often. Sharing would be less wasteful, and libraries already lend things.”

Every idea appeared in the first response. The operational difficulty is unanswered.

Developed follow-up:

“One difficulty is that returned equipment may be damaged in ways that are not immediately visible. The library could address this risk by using a short inspection checklist for each item and leaving time between reservations for staff to test essential functions. For example, a returned drill could be checked for a secure battery, intact casing, and working controls before the next borrower receives it. This procedure would not eliminate every failure, so the library would also need a clear way for users to report faults. The added work limits how large the collection can be, but it does not erase the access benefit of a carefully managed trial.”

The follow-up contributes:

• a new difficulty: hidden damage;
• a mechanism: inspection time and checklist;
• an example: drill checks;
• a qualification: some failures remain and collection size may be limited.

Each unit answers the follow-up rather than restating the original access claim.

Evidence without invented facts

“Add evidence” does not mean fabricate research, percentages, quotations, or authorities.

Unsupported:

“Studies prove that 87 percent of borrowers return tools safely.”

Self-contained reasoning:

“A sign-out record would show which item was borrowed, when it should return, and whether repeated faults occur.”

The second sentence explains what information a system could capture. It does not pretend that a study or statistic exists.

You can use hypothetical examples when clearly framed:

“For instance, if three groups reserve the same camera, a visible calendar could prevent overlapping bookings.”

The conditional if marks the scenario as illustrative rather than factual reporting.

Distinct reason or disguised repetition?

Initial reason: remote meetings save travel time.

Candidate A: “They reduce the time employees spend traveling.”

Candidate B: “They can also include colleagues who live too far away to attend a short in-person meeting.”

A is a paraphrase. B adds an inclusion reason.

Initial reason: community gardens provide fresh produce.

Candidate A: “Residents can grow vegetables to eat.”

Candidate B: “Shared workdays can create regular contact among neighbors who might not otherwise meet.”

A repeats the food benefit. B introduces social contact.

The test is conceptual, not lexical. Different words can express the same reason; repeated words can appear in a genuinely new mechanism.

Controlled practice 1: classify the move

First response claim: “Schools should provide quiet rooms for independent study because some students cannot concentrate in busy common areas.”

Classify each follow-up sentence.

1. “In other words, quiet rooms would offer less busy places to study.”
2. “For example, a student with a free period could use the room to revise without conversations or music nearby.”
3. “The rooms would work only if staff enforce the noise rule consistently.”
4. “Another benefit is that students could join remote tutoring without disturbing others.”
5. “Clear booking limits could prevent one group from occupying the room all day.”

Answers:

1. Paraphrase. It restates the original concentration benefit.
2. Example. It instantiates that benefit.
3. Qualification. It names a condition.
4. New reason/benefit. Remote tutoring differs from quiet individual concentration.
5. Mechanism addressing a potential access problem. Booking limits connect a policy to fairer availability.

Controlled practice 2: answer the actual follow-up

First response: support replacing some parking spaces with bicycle racks because secure parking may encourage cycling.

Follow-up: Who might object to this change, and what concern would they raise?

A. “Bicycle racks encourage cycling because bicycles need somewhere to park.”

B. “Drivers and nearby shop owners might object if the change removes short-term parking used for deliveries or quick visits.”

C. “Cycling is beneficial and bicycle racks come in several shapes.”

Answer: B. It identifies a group and a specific concern. A repeats the original mechanism. C adds an irrelevant feature.

Useful next sentence:

“A limited trial could track rack use and delivery problems before more spaces are converted.”

That adds a response mechanism without claiming that the objection is already solved.

Controlled practice 3: build a mechanism chain

Claim: “Posting meeting agendas in advance can make discussions more focused.”

Put these steps in logical order:

A. Participants can prepare information relevant to each item.

B. Less meeting time is spent discovering basic facts.

C. Participants see the questions before the meeting.

D. The group can spend more time comparing options and deciding next steps.

Answer: C → A → B → D. Advance visibility permits preparation; preparation reduces fact-finding during the meeting; saved time supports comparison and decisions. This is a mechanism, not proof that every meeting will improve.

Build the follow-up around one central addition

Short writing becomes unfocused when it introduces four unrelated ideas. Choose one central addition and develop it through a compact chain:

1. Direct answer to the follow-up.
2. Explanation of why or how.
3. Concrete example or consequence.
4. Boundary, condition, or implication.

These are functions, not fixed sentence openings. Change the order when logic requires it. Do not memorize a paragraph and insert topic nouns.

For the library example, the central addition is inspection burden. Every later sentence develops that issue.

Common mistakes

• Paraphrasing the thesis when the follow-up asks for a new angle.
• Calling a synonym a second reason.
• Giving an example that does not instantiate the claim.
• Jumping from action to outcome without explaining the mechanism.
• Inventing statistics, studies, quotations, or named authorities.
• Adding several unrelated points with no development.
• Reversing the original stance without acknowledging a revision.
• Using a memorized response shape that ignores the customized question.

Final practice pair

Initial prompt: Should employers allow staff to choose flexible starting times?

Write a first response with one benefit and one boundary. Then answer each possible follow-up differently:

1. Give another benefit. Add a conceptually distinct reason, not another version of commuting convenience.
2. How could flexible hours improve work? Explain a mechanism step by step.
3. What problem might occur? Name a concrete coordination difficulty.
4. Give an example. Create a clearly hypothetical employee and situation.
5. When would the policy be unsuitable? State a condition, such as work requiring simultaneous coverage.

Underline the sentence in each follow-up that contains information absent from the first response. If you cannot underline one, revise until the response adds a reason, example, mechanism, or qualification.

For fresh follow-up prompts and development feedback, try Lyra Practice.

Sources

• How the DET measures real-world academic writing
• Research on the Interactive Writing task
• How the Duolingo English Test measures writing

Related

• DET Interactive Writing: answering the follow-up question
• Hedge versus caveat
• Hedge versus qualify
• Flesh out versus outline

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