A group decision system is being built over a network, which has inherent delays due to network lag. Suggest the longest acceptable amount of time the delay could last without affecting the user negatively. Provide an argument for the time you selected.

System confirming the user’s password when logging on.

I believe that from my own experience logging in to systems, thirty seconds is when I begin to become very frustrated.

Synchronous group editing of a document.

Editing of a document should be almost instantaneous. If there are many delays over half a second long, I believe users would become frustrated.

Asynchronous critiquing of other participants’ work.

Because the system is asynchronous, network lag doesn’t matter so much. Even if the network lag is very long, the users will still be able to critique their partner’s work in a timely manner.

Voting on serious issues.

For something the user perceives to be serious, the lag shouldn’t exceed fifteen seconds or else they might begin to become impatient or frustrated.

Discuss three human values that are necessary to be understood by interface designers in order to ensure a timely user experience.

People value feedback, familiarity, and speed.

Provide an argument explaining why delays should be kept short for everyday tasks of a user, using short-term and working memory as the basis for your argument.

Because short-term memory has a very short lifespan, delays must be kept low so that users don’t forget what they are doing.

State a few system response time (SRT) guidelines.

Users prefer shorter response times, longer response times (greater than fifteen seconds) are disruptive, Users’ usage profiles change as a function of response time, etc.