How to evaluate website form filling efficiency using KLM-GOMS analysis Form Efficiency

　　

 

Edit: S ++ Group

In many cases, it is difficult for users to test the efficiency of forms. The common practice is to calculate the efficiency of forms based on the usage or stay time of users after a form is launched, however, this method can only be considered for forms that have been launched. In the design process of a form, is there any scientific way to evaluate the efficiency of the design form?

In 1983 Card, Moran & Newall mentioned The GOMS model for The first time in The Psychology of Human Computer Interaction (The Psychology of Human Computer Interaction). It also set off a storm in The early man-machine Interaction design field.

So what is GOMS?

The so-called GOMS is Goals, Operators, Methods, and Selection Rules. translating them into Chinese is the target, operation, method, and Selection rule.

Goals is the final result of a task.

Operators refers to all actions generated during the process, including using, entering, selecting, clicking, and suspending controls.

Methods describes how to accomplish the target.

Selection Rules refers to the Rules to be determined, that is, different Rules to be followed under different conditions.

Why does GOMS need to be used?

GOMS can objectively record how users perform operations in the form. It also provides scientific analysis methods for complex forms filling processes.

It provides a relatively effective calculation method. In the process of testing different versions, it can simply compare the efficiency of the form design scheme.

Through GOMS, you can obtain credible scientific data to prove the efficiency of filling in the solution of the design form.

Does GOMS have many branches? But what else can we use?

CMN-GOMS, CPM-GOMS model, KLM-GOMS, NGOMSL and many more.

However, in the form-filling GOMS operation, we need to focus on the key-hitting model. KLM (Keystroke-level model ). KML is a simplified model system. It weakens the concept of GOMS and emphasizes O, that is, the operation part. In 1988 Bonnie John further proposed the simplified CPM-GOMS theory.

The KLM model is an 11-step method that can be used to evaluate the time spent on a task that completes simple data input using a computer or a mouse.

This model is used in many human-computer interaction fields. It can accurately calculate the task time required to fill out the overall form through task steps and operations.

Kieras (1993) defines the following operations:

K. Press the key and release (keyboard) (wpm = words per minute)

Optimal Input (135 wpm)-0.08 seconds

Good input (90wpm)-0.12 seconds

Poor input (40wpm)-0.28 seconds

Average skilled input (55 wpm)-0.20 seconds

Average non-linear input (40wpm)-0.28 seconds

Random letter input-0.28 seconds

Complex code input-0.50 seconds

Worst input (different keyboard input methods)-1.20 seconds

P. Point the mouse over the Screen Object-1.10 seconds

B. Press or release the button (Mouse)-0.10 seconds

BB, double-click the mouse-2 sec

H. Move the mouse away from the keyboard or put it for-0.40 seconds.

M. psychological preparation-1.20 seconds

T (n), string type character input (n * K sec .)

W (t), wait for the System user to respond

D (n0, l0), draw a straight line with the mouse using the formula to calculate the required time

Which 11 steps does KLM analyze?

Step 1-Get step-by-step operation instructions for the prototype or task.

Step 2-locate the desired final goal or expected work outcome.

Step 3-find the task flow to achieve the main goal.

Step 4-determine the main target and the task flow in all secondary targets.

Step 5-convert to code.

Step 6-use the code to describe the entire task flow process.

Step 7-retain the psychology or actions of each step.

Step 8-allocate psychology or actions for each step, that is, appropriately Delete unnecessary psychological time.

Step 9-execute the operation.

Step 10-adjust the total task time according to different ages

Step 11-verify the result

However, the use of M (psychological preparation) is critical. M (psychological preparation) how to place is even more important than the precise calculation of other operations. Therefore, make sure to use the same M placement rules when comparing different design versions.

Therefore, we have the following suggestions on how to place and handle M (psychological preparation:

When you start a task, you have to stop and clearly understand what to do for the task.

To make a decision, if there are multiple ways to perform the task, then the user (not very familiar with the task or the decision is not obvious) before making the decision) often stop thinking.

It takes some time to think about getting information from the memory, such as the name of the recall file, the command character, or the abbreviation.

Find some information on the screen. the user must stop and then browse the screen to find the location where they can't predict some information through experience.

Considering the task reference value, users sometimes remember to read parameters. In this case, they need to consider whether to add M (psychological preparation ).

Check behaviors are right or wrong. users usually stop and check their information or their portal before submitting the system response.

There are some general principles for M (psychological preparation) placement on webpages:

K (hitting the keyboard), P (moving the mouse to the target), B (clicking the mouse), M (psychological preparation), W (waiting for system response ).

In principle 1, input content (such as all K, P, and B) is added to M at the beginning.

For example, if you move the mouse to a target, and then you click the target (press the mouse button) or adjust the target, then in principle 1, your time calculation is, MPMB;

Principle 2 remove predictable M. If the action after M can completely deduce the action before M, remove this M.

For example, when you browse an image, you can click an image to view the next image. As a user who has been using the image for a long time, he knows the effect of this operation, in this case, the computation becomes MPB;

Principle 3 Remove M from a series of identical actions and delete all M except the first M.

For example, enter four letters "soso", follow principle 1, mkmkmkmk, and follow this principle MKKKK;

Principle 4 remove M before the command Terminator. M can be deleted if the operator follows a long string and is used for a long time.

For example, if you are familiar with the login form, you can delete M after entering the user name and using the tab to switch to continue entering the password.

For example, if you enter a command character and know the effect of the command, you can ignore the M before you press enter to execute the command. However, if you click a button, you will not be able to predict the effect after clicking the button, or the clicking of the button may cause psychological pressure. In this case, M still needs to be added back.

For example, when the purchase button appears, many users may hesitate, And the deletion button is the same;

Principle 5 remove repeated M

When W occurs, that is, the system response time, M needs to be deleted.