Data Analysis and Interpretation Techniques for Human-Computer Interaction

Human Computer Interaction

Requirements (Part 2) 1. Data Analysis and Interpretation 2. Techniques of data analysis 3. Task Description 4. Task Analysis

Data Analysis and Interpretation The kind of analysis that can be performed on a set of data will be influenced by : 1. goals identified at the outset 2. data actually gathered. Broadly speaking, you may take a qualitative analysis approach a quantitative analysis approach In a combination of qualitative and quantitative. The last of these is very common as it provides a more comprehensive account of the behaviour being observed or performance being measured. Most analysis, whether it is quantitative or qualitative, begins with initial reactions or observations from the data. Interpretation of the findings often proceeds in parallel with analysis, but there are different ways to interpret results and it is important to make sure that the data supports your conclusions.

Techniques of data analysis: 1) Quantitative data : is data that is in the form of numbers, or that can easily be translated into numbers. For example, the number of years experience the interviewees have, the number of projects a department handles at a time, or the number of minutes it takes to perform a task. 2) Qualitative data: is not expressed in numerical terms. For example, qualitative data includes descriptions, quotes from interviewees, vignettes of activity, and images.

Simple Quantitative Analysis. Averages and percentages are fairly well-known numerical measures. However, there are three different types of average and which one you use changes the meaning of your results. These three are: mean, median, and mode. Mean : refers to the commonly understood interpretation of average. Median : is the middle value of the data when the numbers are ranked. Mode : is the most commonly occurring number. Median and mode are less well-known but are very useful. For example : in a set of data (2, 3, 4, 6, 6, 7, 7, 7, 8), the median is 6 the mode is 7, the mean is 50/9 = 5.56. In this case, the difference between the different averages is not that great. However, consider the set (2, 2, 2, 2, 450). Now the median is 2, the mode is 2, and the mean is 458/5 = 91.6!

Simple Qualitative Analysis. There are three simple types of qualitative analysis, which include: 1- Identifying recurring patterns and themes 2 - Categorizing data 3- Analysing critical incidents. These are not mutually exclusive and can be used in combination. Tools to Support Data Analysis. Two well-known tools that support some of these data analysis activities are Nvivo and Atlas.ti. SPSS (Statistical Package for the Social Sciences) Is one of the more popular quantitative analysis packages that supports the use of statistical tests. It is a sophisticated package offering a wide range of statistical tests such as frequency distributions, rank correlations (to determine statistical significance), regression analysis, and cluster analysis. SPSS assumes that the user knows and understands statistical analysis.

Task Description Descriptions of business tasks have been used within software development for many years. We shall introduce three of the more common description types here: 1. Scenarios 2. Use cases 3. Essential use cases (sometimes referred to as task cases). 1- Scenarios A scenario is an informal narrative description (Carroll, 2000). It describes human activities or tasks in a story that allows exploration and discussion of contexts, needs, and requirements. Scenarios and Personas The difference between personas and scenarios can be difficult to grasp at first. Although reading about it may seem clear, it is a common confusion to end up combining the two. A scenario describes one use of a product or one example of achieving a goal, A persona characterizes a typical user of the product.

The relationship between a scenario and its associated persona

2- Use Cases Use cases also focus on user goals (actor s goals), but the emphasis here is on a user system interaction rather than the user's task itself. They were originally introduced through the object-oriented community in the book Object- Oriented Software Engineering (Jacobson et al, 1992). Use case diagram for the travel organizer showing four use cases and two actors

3- Essential Use Cases. Essential use cases (also referred to sometimes as task cases) represent abstractions from scenarios, i.e. they : 1. Represent a more general case than a scenario embodies, 2. Try to avoid the assumptions of a traditional use case. An essential use case is a structured narrative consisting of three parts: 1.Name that expresses the overall user intention 2.Stepped description of user actions 3.Stepped description of system responsibilities.

Task Analysis Task analysis: is used mainly to investigate an existing situation, not to envision new products. It is used to analyse the underlying rationale and purpose of what people are doing: 1. What are they trying to achieve 2. Why are they trying to achieve it. 3. How are they going about it? The information gleaned from task analysis establishes a foundation of existing practices on which to build new requirements or design new tasks. The most widely used version is Hierarchical Task Analysis.

H.W Q1) What are the techniques of data analysis? Compare between them. Q2) What are the types of task description? with discuss Q3) Define the task analysis and What it the purpose for it?