Not Really a Blog

June 21, 2006

Extreme Temperatures

Filed under: Random — Tags: , — jesus @ 04:14

It seems that Seville holds the record for extreme maximum temperature in Europe. I found out accidentally reading the wikipedia. As sometimes the wikipedia is regarded as not being trustworthy (as anyone can change it), I wanted to look for an official website and found one at the National Climatic Data Center (from the National Oceanic & Atmospheric Administration ) in which it is confirmed.

But, as some might think that the 19th century is too far away, have a look at this graph from 2003 in Seville . But, if you are amazed by the maximum temperature, have a look at the minimum at 02:00. By the way, those temperatures were measured in the shade.

temperature in Seville - Aug 2003

Note: If the link above does not work, try this one at flickr

Note2: Thinking of going to Seville? Better avoid July and August.

June 8, 2006

User-Centered Design

Filed under: Computers — Tags: , — jesus @ 04:24

Following my last post about human-computer interaction, I am going to talk a little bit about User-Centered Design which is a methodology to achieve a good human-computer interaction.

So, what is User-Centered Design…

A design method

User-Centered Design (UCD) is a design methodology that is about
designing interactive technologies to meet users’ needs. We can divide it in
four stages:

  1. Understand users’ needs
  2. Establishing requirements
  3. Prototyping
  4. Evaluanting designs

Its key characteristics are:

  • Understand users and their needs
  • Focus on users early in the design and evaluation.
  • Identify, document and agree specific usability and users experience goals
  • Iteration

We would like to use this methodology because using it would help us to

  • more likely build something useful
  • manage users’ expectations
  • Encourage ownership of the solution
  • Easier integration

That’s it, the user is the key in the design of any interactive product, something many
vendors or software developers don’t consider quite oftenly

Understanding Users’ Needs

It is vital to understand what users would want from or would want to do with a
interactive product. Many failures in this regard leads to unused, difficult or awkward
products and basically come from ignoring what users of that specific artifact
need and want.

To achieve this, we need to use certain Data Gathering Techniques in order
to retrieve as much information as possible. So we could use a range of research methods:

  • Observation: Using anthropology methods to observe people and draw conclusions.
  • Interviews: They are good as an initial approach to what users want, but sometimes they might
    be unfeasible (too many people, time-consuming, etc.)
  • Questionnaires: A serie of questions to elicit information from the users. They are good to retrieve
    quantitative and cualitative data.
  • Focus Groups: They are group interviews, and are good to understand the users’ need from a global
    point of view. (ie. to get consensus)
  • Analysis: Extract conclusions from the aforementioned methods.

Establishing requirements

This is to deal with the typical questions: What do users want?, What do users need?… etc.
As anyone who has done some software engineering, there are
different requirements:

There might as well be other requirements, such as physical (noisy
environment, dusty, etc…), social (sharing of files, displays,
etc…) or organizational (hierarchy,
communications, etc.) that may be addressed as well.


It is also vital to do prototyping, that is create mockups of the
system or simmulations to test them. It does not need to be a final
prototype, it can be done with paper in its initial stages, and, once
its being defined, get a more-closer-to-the-final-product
prototype. That’s why there are different kinds of prototypes that can
be done:

  1. Lo-Fi prototype: Basically made with paper, post-it notes, etc. Provides a quick and dirty look.
  2. Mi-Fi prototype: simulated functionality. They are based on screen printouts or screen simulations.
  3. Hi-Fi prototype: Almost like the final product, resembling it.

Evaluating Designs

There needs to be an iterative process evaluating the prototypes,
from the early stages of the project throughout the final prototypes.
This would help get the right design from the very beginning and reduce
errors or prevent from getting a final product that is unusable. Also,
it would help to extend the functionality.
We can have two different types of evaluation:

  • Formative Evaluation: Done throughout the process.
  • Summative Evaluation: Done when the process is finished

In order to evaluate, there are a variety of ways to do it, depending if its from a user’s point of view or from
a group of experts’ point of view. These are:

  • Quick & Dirty: Informally asking users for feedback.
  • Usability testing: Recording typical users’ tasks in controlled settings
  • Field Studies: Observation in natural settings (where the interaction is taking place)
  • Predictive evaluation: Asking experts to apply knowledge of typical users.

Disclaimer: These notes are not my own creation. They are mostly based on what I have been studying
and summaries I have been using. My sources include
John Halloran’s lecture notes and the book Interaction Design by Rogers et al.

Human-Computer Interaction

Filed under: Computers — Tags: , — jesus @ 04:22

So, as I said in a previous post, I am taking a course on Human-Computer Interaction, a subject that deals with almost everything that involves our everyday lives. Who has not used a mobile phone? a computer? a vending machine? Even a simple elevator, that would seem to most people unrelated to computers, has to do with HCI, the interaction between a person and the thing in question.

The textbook on which the course is based is Interaction Design, beyond human-computer interaction by Rogers, Sharp and Preece, on which most of these notes are taken.

Human-Computer Interaction

So, back to computer-enabled gadgets such as mobile phones, mp3 players, PDAs and, obviously computers, it is a relly really important topic. How many times have you felt awkward using a mobile phone or a program or web application? Why are some applications that make you feel easy while some others annoys you?

That’s Human-Computer Interaction and it is a topic that could be defined as

The study of interaction between people and computer-based systems

and usually concerns with the physical, psychological and theoretical aspects of this process, as Rogers defines in his book Interaction Design.

So, we should use HCI to develop usable products:

  • Easy to learn
  • Effective to use
  • That provide an enjoyable experience

and avoid bad designs that causes problems.

How to design products properly?

Any good design involves understanding how users interact with computers and enabling them to do so effectively. Failing to do this leads to awkward designs.

There are a number of methods and techniques to make this happen. One of them is User-centered design (UCD) in which all design depends ultimately on the user’s needs, made in an iteratively way.

What to take into account

We would need to take into account:

  • Who the users are
  • What activities are being carried out
  • Where the interaction is taling place

There are a number of usability goals that we would like to achieve:

  • Effectiveness: How good a system is at doing what it is supposed to do.
  • Efficiency: The way a system supports its users in carrying out their tasks.
  • Safety:Protecting the user from dangerous conditions and undesirable situations.
  • Utility: The extent to which the system provides the right kind of functionality so that users can do what they need or want to.
  • Learnability: How easy a system is to learn to use.
  • Memorability: How easy a system is to remember how to use, once learned.

So now, if you have ever developed a program, web application, think about these usability goals. To what extent were they supported in your application? Did you find it easy to use? Did other people, even non technical, find it easy to use? How would you improve it?


Think about all this. I’ll think about it too ;-) and post some more info about User Centered Design and other related stuff in the near future :-) .

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