Professional Courses
Industry-relevant training in Business, Technology, and Design to help professionals and graduates upskill for real-world careers.
Categories
Interactive Games
Fun, engaging games to boost memory, math fluency, typing speed, and English skillsβperfect for learners of all ages.
Typing
Memory
Math
English Adventures
Knowledge
Interactive Audio Lesson
Listen to a student-teacher conversation explaining the topic in a relatable way.
Introduction to KLM and Its Operators
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Exactly! KLM helps us predict how long it will take an expert user to complete a task using an interface. It does this by breaking down the task into observable actions or operators.
What are some of these operators in KLM?
Great question! Some key operators include: K for Keystroke, P for Pointing, H for Homing, M for Mental Preparation, D for Drawing, and R for System Response. Remembering these can be easier if we think of the acronym KPHMDR.
So, what does each operator represent?
K represents a keystroke, P is the movement to a graphical element, H means moving between input devices, M stands for mental preparation, D is used for drawing tasks, and R is for the system's response time. Now, letβs summarize the concepts: KLM helps measure task time efficiently, breaking interactions into these operators.
Applying KLM: The Copy-Paste Task
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Moving on, letβs apply KLM to a common interaction. Imagine you want to copy text using a context menu. How would you break down this task?
I think you start by moving the cursor over the text you want to copy.
Right! After positioning the cursor, you would right-click. What operator is that?
Thatβs a button click, represented as B!
Exactly! Let's create the operator sequence for this task. We'll include mental decisions and think through the timing for each operation.
So we document every step: M for deciding to copy, then P for moving to the copy option.
Well done! Now after calculating the execution time for the entire sequence, what key conclusions can we draw?
It shows how different interaction methods yield different time efficiencies!
Calculating Execution Time with KLM
Unlock Audio Lesson
Signup and Enroll to the course for listening the Audio Lesson
Let's focus on calculating execution time. How do we sum up the times for each operator?
We take the average time for each operator and multiply by how many times we use it, then sum them up!
Exactly! For our copy-paste task, if we identified 4 M's, 4 P's, and 6 B's, how do we calculate the total?
Weβd do (4*1.35) + (4*1.1) + (6*0.1) + 2R!
Perfect! Now does anyone want to calculate it for practice?
Yes! That would be 10.4s plus the system response time!
Well done! Remember how crucial these calculations are for optimizing interfaces.
Introduction & Overview
Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.
Quick Overview
Standard
The section demonstrates the application of the Keystroke-Level Model (KLM) through a concrete example of copying text using a context menu and pasting it with a keyboard shortcut. It breaks down the user actions into KLM operators and calculates the total predicted execution time, highlighting the efficiency differences between various methods.
Detailed
The Keystroke-Level Model (KLM) serves as a powerful tool in quantifying the interaction times for expert users performing routine tasks. In this section, we illustrate the KLM process by analyzing the task of copying text via a context menu and pasting it with a keyboard shortcut. The example includes a meticulous decomposition of user actions into specific KLM operatorsβmental preparation (M), pointing (P), button clicks (B), and system responses (R). By systematically applying KLM to our example, we calculate the total execution time, assisting in comparing different user interface methods, revealing insights into task efficiency, and justifying design decisions based on quantifiable data.
Audio Book
Dive deep into the subject with an immersive audiobook experience.
Task Definition
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
An expert user wishes to copy selected text from one location and paste it into another, utilizing a mix of mouse-based context menu for copy and a keyboard shortcut for paste.
Detailed Explanation
In this example, we outline a simple task: an expert user wanting to copy text from one part of a document to another. The user will use a context menu (right-clicking with the mouse) to initiate the copy action but will employ a keyboard shortcut (Ctrl+V) to paste it. By establishing this task, we can apply the Keystroke-Level Model (KLM) to evaluate the time it takes to perform each action involved in the task.
Examples & Analogies
Think of this task as a student needing to copy a quote from a book theyβre reading (the context menu action) and then pasting it into a document (the keyboard shortcut). The student is skilled and knows how to use both methods efficiently.
Proposed Method (User Actions)
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
- User has already selected the text to be copied (this preliminary step is outside the scope of this specific KLM calculation but would precede it).
- Mentally decide to copy the text using the context menu.
- Move mouse cursor over the selected text.
- Right-click the mouse to open the context menu.
- Mentally locate the "Copy" option in the menu.
- Move mouse cursor to the "Copy" option.
- Left-click the "Copy" option.
- System processes copy (brief R).
- Mentally decide where to paste.
- Move mouse cursor to the desired paste location.
- Left-click at the paste location (to set insertion point).
- Mentally decide to paste using the keyboard shortcut.
- Press Ctrl key.
- Press V key.
- System pastes text (R).
Detailed Explanation
Here, we describe the detailed sequence of actions the expert user takes to copy and paste text. The actions include mental preparations (deciding to copy and where to paste), physical movements (moving the mouse and clicking), and interactions with the system (such as right-clicking to open the context menu). Each specific task, like identifying the 'Copy' option or ensuring the cursor is at the right spot for pasting, is included in this action sequence to ensure a comprehensive analysis of the entire process.
Examples & Analogies
Imagine the user is like a chef preparing a dish: first, they decide what ingredient to add (mental decision), then they reach for it (movement) and chop it up (action). Similarly, in this task, each step leads toward a final goal β getting the text copied and pasted correctly.
KLM Operator Sequence (Applying Heuristics)
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
M (decide to copy)
P (move mouse over selected text)
B (right-click to open context menu)
M (locate "Copy" option in menu - Rule 1: not direct response)
P (move mouse to "Copy" option)
B (left-click "Copy" option)
R (system processes copy)
M (decide where to paste, then decide to use keyboard shortcut - Rule 4: combine related Ms)
P (move mouse to paste location)
B (left-click to set insertion point)
H (home hand from mouse to keyboard)
K (press Ctrl)
K (press V)
R (system pastes text).
Detailed Explanation
In this section, we condense the user's actions into a sequence of KLM operators which include physical, cognitive, and system response actions. The sequence is critical for understanding the time it takes for executing each operator. Each operator is categorized: 'M' for mental preparation, 'P' for pointing with the mouse, 'B' for button interactions, 'K' for keystrokes, and 'R' for system responses. This breakdown helps us see how each action contributes to the total time it takes for the complete task, thus analyzing efficiency.
Examples & Analogies
Think of this operator sequence like a musician following a sheet of music: each note they play (or request to play) corresponds to a specific action that, when put together, creates a complete piece. Just as the musician must move fluidly from one note to the next, the user must seamlessly transition from one action in the sequence to effectively complete the copy-paste task.
Calculating Total Execution Time
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
Count operators: 3M, 3P, 3B, 1H, 2K, 2R
Total Time = (3 * M) + (3 * P) + (3 * B) + (1 * H) + (2 * K) + (2 * R)
Total Time = (3 * 1.35) + (3 * 1.1) + (3 * 0.1) + (1 * 0.4) + (2 * 0.28) + 2R
Total Time = 4.05 + 3.3 + 0.3 + 0.4 + 0.56 + 2R
Total Time = 8.61s + 2R.
Detailed Explanation
Now that we have our sequence, we can calculate the total predicted execution time for the task. Each operator has an average time that we multiply by the number of times it appears in our sequence. By summing these multiplied values together, we arrive at the total estimated time needed to complete the entire copy-paste operation. 'R' indicates system response time, which can vary based on the specific system used.
Examples & Analogies
This calculation is like a project manager evaluating how long a project will take by considering each task's time and how often it occurs. If each plant needs a similar 30-minute setup, and there are 10 plants to set up, the manager combines all the times to see how long the overall project will last.
Comparative Example: Entirely with Keyboard Shortcuts
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
Copy-Paste entirely with Keyboard Shortcuts (Ctrl+C, Ctrl+V):
(Mentally decide to copy)
K (Ctrl)
K (C)
R (system processes copy)
M (decide where to paste, then decide to use keyboard shortcut)
H (if hand not already on keyboard - omit if already there)
K (Ctrl)
K (V)
R (system pastes text)
KLM: 2M, (0 or 1 H), 4K, 2R
Total Time (assuming H=0): (2 * 1.35) + (4 * 0.28) + 2R = 2.7 + 1.12 + 2R = 3.82s + 2R.
Detailed Explanation
In this section, we analyze a different method for performing the same task: using only keyboard shortcuts. The sequence is broken down into KLM operators just as earlier. This method is likely to be quicker because it minimizes pointing and clicking, demonstrating the total time required for the keyboard-only operations. The assumption is made that the fingers are already positioned over the keyboard, simplifying the process.
Examples & Analogies
Picture a race between two delivery drivers: one uses a car filled with tools (mouse operations) while the other rides a bike directly to the customer (keyboard shortcuts). The bike rider can get through traffic quickly, while the car driver spends time maneuvering through obstacles, demonstrating that streamlined, focused methods reduce the total time taken to get the job done.
Conclusion from Comparison
Unlock Audio Book
Signup and Enroll to the course for listening the Audio Book
The pure keyboard shortcut method (3.82s + 2R) is significantly faster for an expert user than the mixed mouse-keyboard approach (8.61s + 2R), primarily due to the elimination of multiple pointing and clicking actions and homing time.
Detailed Explanation
The analysis has shown a clear takeaway: using the keyboard shortcuts drastically reduces the time needed to perform the same task compared to a method involving both mouse and keyboard operations. This highlights the importance of minimizing unnecessary steps for efficient task execution. The time saved reflects significant gains in productivity, especially for expert users who are familiar with the shortcuts.
Examples & Analogies
Imagine an experienced chef versus a novice in the kitchen: the experienced chef knows exactly where all the tools are and how to use them quickly, while the novice may fumble about, looking for ingredients and tools. Streamlined processes, like using keyboard shortcuts, mirror the efficiency of a well-practiced chef β they enable faster work and smoother flow.
Definitions & Key Concepts
Learn essential terms and foundational ideas that form the basis of the topic.
Key Concepts
-
KLM Operators: K (Keystroke), P (Pointing), H (Homing), M (Mental Preparation), R (System Response)
-
Task Execution Time: The total predicted time to complete a task derived from summing operator times.
Examples & Real-Life Applications
See how the concepts apply in real-world scenarios to understand their practical implications.
Examples
-
Copy-paste operation involving context menus and keyboard shortcuts.
-
Different execution times calculated for various user interface methods.
Memory Aids
Use mnemonics, acronyms, or visual cues to help remember key information more easily.
π΅ Rhymes Time
-
When KLM's in play, here's what to say, K for keystroke, P points the way.
π Fascinating Stories
-
Imagine a user preparing to send an email; they mentally rehearse (M), point to the send button (P), click with glee (B), and wait for system response (R).
π§ Other Memory Gems
-
KPHMDR: Keep People Happy, Monitor Decisions Responsively; it helps remember KLM's key operators.
π― Super Acronyms
KLM
- Keystroke
- Pointing
- Homing
- Mental Preparation
- System Response.
Flash Cards
Review key concepts with flashcards.
Glossary of Terms
Review the Definitions for terms.
-
Term: KeystrokeLevel Model (KLM)
Definition:
A model that predicts the time required for expert users to complete tasks by decomposing them into observable actions.
-
Term: K (Keystroke)
Definition:
An operator representing the act of pressing any key or button.
-
Term: P (Pointing)
Definition:
An operator referring to the movement of a pointing device to acquire a target.
-
Term: H (Homing)
Definition:
An operator that represents the movement of the user's hand between different input devices.
-
Term: M (Mental Preparation)
Definition:
An operator signifying the cognitive processes involved in making decisions before executing an action.
-
Term: R (System Response)
Definition:
An operator indicating the time taken by a system to respond to a user's action.