• Participants signing-up to studies come from a selected population (for example, high-adherers) | • Participants using internet (selection bias is internet users) |
• Patients aware that their behaviour is being monitored (reactivity and self-representation biases) | • No reactivity or self-presentation bias |
• Data collected are prompted by pre-structured research questions | • Self-initiated views with no time, length, or behavioural constraints |
• Data mediated/focused through research facilitator | • Data stem from participants’ agenda |
• Time consuming: small set of data | • Semi-automatic: large set of data |