SCADA HMI Input Devices

HMI, HCI, MMI request for information

Tue, 5 Aug 97 09:10:27 -0400

I am conducting a systems analysis to develop the best alternative for some combat systems interface. I recall that there has been discussion on HMI, HCI, etc. I am looking for information that will help me compare different alternatives. What comparisons have been made for touch screen versus key board input as an example? Also, there is one definite performance measure: Time

Can anyone help me with locating infomation on this? Also, based on the various expertise, can anyone offer some additional indices of measurement (performance measurements)? Are there some human factors that I must address? Any help is appreciated. Barry

******************************* [:-)] *******************************
*                                                                   
*     Barry Ezell                                                      
*     Captain, United States Army                                      
*     bcezell@aol.com                                                  
*     bce4k@virginia.edu                                               
*     Graduate Student, Systems Engineering, UVA                       
*     804 975 3525 (home)                                              
*     Home page:  http://watt.seas.virginia.edu/~bce4k/barry.html 

Re: HMI, HCI, MMI request for information

Tue, 05 Aug 1997 22:36:13 +0100

Barry Ezell wrote: Barry I am doing my thesis on HCI for Industrial Applications, and there has been extensive work done on measuring differences between various input devices. Much of the results are inconclusive, but the following is a summary from various studies undertaken over the last decade.

		Cursor	Mouse	JoyStick  Trackball	TouchScreen	Touch Tablet

Speed		Slow	Fast	Medium	  Medium	Fast		Medium

Accuracy	High	Medium	Medium	  High		Low		Medium

Speed Control	Some	Yes	Some	  Yes		Yes		Yes

Continuous
movement	No	Yes	Some	  Yes		Yes		Yes

Fatigue		Low	Medium	Medium	  Medium	High		Medium
If time is the only crucial measurement you have, then how information is displayed on the screen is much more important than what type of input device you use. Regardless of how the user makes a choice, the longest part of the selection process is deciding where on the screen the required selection is.

For example one study done by Card et al is as follows:

Total Response Time	Error Rate		Device
1.66			5			Mouse
1.83			11			Joystick
1.91			9			Touch Tablet
2.51			3			Cursor Keys
As can be seen the touch tablet is quite slow, and has a lot of errors. This surprises many people because pointing is such a simple operation, but if one thinks about it, when your big pudding hands are on the screen it makes it obscures other parts of the screen. Generally mouse or trackball input is seen as the best all round solution, but it depends on other factors.

There are several good books available on HCI. Anything by Ben Shneiderman is worth looking at. Human Computer Interaction by Mary Pierce is also a good bet. For a good overview on device selection try Software User Interface Design by Deborah Mayhew.

I hope this has helped a bit, and feel free to ask away. Cheers

-- 
James Winters
jwinters@innotts.co.uk
http://innotts.co.uk/~jwinters/
+44 (0)1623 459576

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