Your argument will be more compelling if you can refer to some specific evidence and introduce some plausible limits.
Here are a few reminders to help you:
Possible sources of evidence
- Personal experience (from yourself and others)
- Observations (live and recorded)
- Surveys and questionnaires
- Published research (from books and articles)
- Authority opinion & expert testimony
- Hypothetical scenarios
Limits
- Scope (where this argument applies)
- Certainty (how confident you are about your claims, evidence, etc).