Radio Buttons & Check Boxes
The event generated when the user interacts with these controls is not a click event as it is when the user interacts with a button, but a CheckChanged event. This is because when the user clicks on these controls, they intend to change the current status of the control. A problem occurs when a beginning programmer, or one new to VB, assumes that a click means the user is selecting (turning on) that option. It is actually just as likely that the user is deselecting or turning off that option.
Think about the operation of a Check Box compared to a Radio Buttons. Check boxes have to be deselected by the program user whereas Radio Buttons are automatically deselected for the user when they click on a different radio button.
So, does clicking turn the check on or does it turn the check off? Truthfully it can do either one. If the check is currently on then clicking it will turn the check off and vica versa. This is precisely the reason why the procedure is named CheckChanged. It is changing the check from its current state to the opposite state. Radio buttons and Check boxes are controls which alter the state of something in a program. Buttons are controls which activate an event procedure. If a programmer forgets that the Radio button and Check box event is CheckChanged, their coding will generate peculiar and unreliable results. Here is a program you can download which demonstrates this behaviour.
The most important effect of this, is that when we code using these controls, we must not assume that the user event is turning the state of the control on, rather it is changing the state of the control. It might be turning the control off. The easiest way to cope with this ambiguity when coding is to always use a Forced Choice selection structure. Explicitly check the state of the control by testing the Checked property of the control. Then provide one set of commands to be executed if the control is being selected, and another set of cammands to be executed if the control is being deselected. This way we can code the event to respond appropriately whether it is turned on or whether it is turned off. Typical code would look like this:
If EmailOptIn.Checked then
optIn = True
optIn = False
This is better code - more reliable - than using just a conditional and incorrectly assuming that the user is always turning the control on. Making assumptions about the state of controls in programming always causes problems sooner or later.
The Short and Glorious History of Organizational Behaviour
The study of how people behave in organizations is useful to all organizational participants. It helps the top level participants understand how to manage the organization. It helps managers become better at controlling their departments. It helps lower level participants understand why things are the way they are and how to protect themselves against being victimized by a system that appears to largly take them for granted. It offers help in understanding orgaizations from operational, tactical and strategic viewpoints.
One interesting introduction to this field, and a favourite of mine, is an overview written by Charles Perrow entitled "The Short and Glorious History of Organizational Theory". The article was originally published in Organizational Dynamics (Summer 1973). I read it in a compilation called Classics of Organization Theory while in a masters program in the early 1980's. The author employs a tongue in cheek style and renders the history as a struggle between the forces of light and the forces of darkness. What follows is my synopsis of Perrow's article.
Perrow characterizes organizational history in terms of two main forces. Those forces of research which treated an organization as a mechanical thing, he characterizes as the forces of darkness. The forces of light collectively refer to research that has a more humanistic basis and theme. "From the beginning, the forces of light and the forces of darkness have polarized the field of organizational analysis and the struggle has been protracted and inconclusive." The forces of darkness refer to such things as Taylorism (father of time and motion studies), division of labour, specialization, and line of authority. The forces of light comprize the human relations movement, Hawthorne studies and related themes. These aspects of organizational investigation emphasize people, accomodations and biological analogies over mechanical ones.
Scientific ManagementThe show gets started with the rise of Scientific and Classical Management. Emphasis was on planning, record keeping, reduction of span of control to about six, decisiveness and other rather simplistic pronouncements. The primary examples of organizations were the military and the Catholic church and organizations were seen as mechanical entities. As organizations expanded, most of these admonitions worked. However, the one constant in human affairs is change, and several factors arose which were problems for the formulae of the time. These included:
- Increasing importance of Labour accompanied by its rise in power.
- Increasing diversity of markets, proliferation of products, and increased complexity of technology.
- Changes in cultural, political and social changes altered the expectations of the general population with respect to the workplace.
- As growth increased organizations became too large and diverse to be seen as an extension of their owner. Mergers proliferated and a general preoccupation with management and leadership emerged.
Enter Human RelationsAlthough some individuals had opposed Scientific management they were mostly ignored. However, these voices received a tremendous boost from the publishing of two studies. The first was a book by Chester Barnard who proposed the theory that an organization is a "cooperative system" rather than a mechanical system. Then came the Hawthorne studies which emphasized the importance of human factors such as informal work groups, norms, and social relationships and their effects on productivity.
Attention then turned to the study of leadership. At first the emphasis was on leadership traits and the list sounded, as Perrow stated, "like an enumeration of Boy Scout qualities: kind, curteous, loyal, courageous". The research did turn up differences between employee centered aspects of leadership (consideration) and job centered aspects of leadership (initiating structure) and this provevd to be a fruitful area of investigation. It also bolstered the human relations approach to the study of organizations.
The Tavistock investigations into what is now known as sociotechnical systems also found important relationshsips between productivity and work groups. The practical negative impact of actions such as routine tasks, submission to authority, specialization of task, ignorance of the goals of a firm and centralized decision making on a group's morale were well documented. Another interesting discovery was how social systems interacted with job task considerations. Far from having only a negative influence on work productivity, social interaction was found, under certain circumstances, to improve work productivity.
The pace of change of technologies and the turbulence of the environment brought new views of how organizations ought to be organized. Models of the organization began to move toward organic and social systems rather than mechanical. While the models became much more complex, most agreed the models were much more realistic and very much more revealing.