Game as an Interactive Interface

Gameplay Usability

Taras Korol, Ubisoft Kiev

Ubisoft approach

Avoid confusion

Signs Cues to provoke action. Provide information

about the state of the system

FeedbackA response to a player’s actions. Provides information about the consequences of these actions

PerceptibilityTo be useful, information has to be seen / felt or heard, ie perceived.

ConsistencySimilar things have similar meanings & similar behaviors

Ubisoft Game Usability Criteria

Make playing comfortable

Minimum workloadActions outside the gameplay loop should

require minimum efforts from the player

Error managementFor actions not related to the game loop, help the players to prevent fatal errors andsolve errors when they occur

FlexibilityEach player is unique. Players should be able to customize the game to suit their needs and preferences.

Taken from U-Learn Accessibility Training presentation

Introduction to UI and Cognetics

Interface is a set of means for interaction between human and system

Cognetics is an ergonomy of human mind and perception

People are limited in their memory and processing resources

Attention and Memory

Attention limitations

Locus of attention can only be allocated at one spot at a timeMost of illusionist tricks are about manipulations with locus of attention. Multitasking in fact is an illusion that derives from the ability of rapidly switching the attention. Note that word “attention” does not have plural form in any of the languages. Simply because multiple attentions do not exist. Most commonly, locus of attention is allocated where the action is about to be applied, so it is likely to be where mouse cursor or crosshair is. Note that the cursor or crosshair itself is not the subject of attention.

Switching between complex tasks takes about 10-20 secondsExperiments proved that performing two tasks one after another is significantly more effective than while constantly switching between them. This fact is especially important in real time strategy design where frequent switching of attention is very common thing.

Attention limitations

Automaticity is a workaround to attention limitations

Automated reflectory actions do not require attention which allows for example

driving and talking at the same time. In game design, forming of reflexes plays a huge part in learning curve design. A game “This is the only level” is wholly based on tricks with automaticity

Pitfalls of automaticity

Automated actions are poorly manageable. Switch pedals in a car, warn the driver,

place reminders before his eyes, but in critical situations reflexes will still take over.

“This is the only level” gameplay is wholly based around automaticity

Nothing changed on stage 20 except the level is invisible. This is one of the easiest stages though

Long-term memory

People are unable to memorize random dataThe ability to memorize random data is in fact an ability to provide sense to meaningless patterns

Memorizing via contextual connectionsThe most common way to memorize things is to associate them with something previously known

Memorizing via explanatory mechanisms – the power of constrains

There may be no need to memorize what can be recalled by applying logic. Thus a

rhyme allowed bards of the past to remember very long poems by limiting or eliminating alternatives.

Memorizing via repetitionPeople can miss up to 60 % of spoken or written information. Repetition is another chance to create different association. If repetition involves physical actions it addresses a whole different layer of memory

Short-term and procedural memory

Short-term memory is limited to average 7 entities5-9 entities is all we can grasp at a time. This explains “Less is more” statement. People deal with this limitation by grouping entities. For example a car is a huge conglomerate of details, but is represented as a single entity in human mind

Procedural memoryProcedural memory is the type of memory responsible for remembering how to perform actions. A whole different part of the brain is used. In numerous brain-injury caused amnesia cases people didn’t remember their life but remembered perfectly how to dress or how to eat. Mixing theory with practice is very effective because procedural memory can act as a reminder – that’s why tutorial missions are better than briefings.

Muscle memoryMuscles have their own memory, so the hands “know” the movement they should perform. This is a type of procedural memory. Musician can forget how the melody sounds, but his finger still remember how to play it. Be careful with automatic adjustment of mouse sensitivity and screen resolution – hands get used to it.

Designing for memory

Do not rely on human memory!!!

If your design suggests that player has to remember something to complete the game,

it is a bad design. There always should be clues and reminders. Keep all game-important information stored in one place (journal, Civilopedia, diary, whatever)

Limit the load on memory

Give no more than 5-7 entities to remember at a time. The less is the better.

Exploit associations

Give you characters meaningful names (Max Payne, Blood Rayne, Alan Wake), give

landmarks recognizable shapes, make them visible.

Designing for memory

Merge entities into groupsGrouping significantly reduces load on memory and attention. A car is an extremely complex conglomerate of elements but mind addresses to it as to one thing.

This is how Mass Effect 2 HUD would look without grouping. Try to remember where is what.

Designing for memory

Merge entities into groupsMake groups clearly separated both visually and spatially

And this is the magic good grouping can do

Designing for memory

Repeat

It may be a good idea to build important dialogue using repetitive key words. This is a

basic trick of NLP and rhetoric. Repetitive actions are a key to mastering the game and the amount of repetitions is directly related to learning curve

Hide the unimportantProgressive disclosure allows showing less important things only when they are needed.

Provide context where possible Information is interpreted depending on context. Context is a perfect reminder

Designing for memory

Repeat

It may be a good idea to build important dialogue using repetitive key words. This is a

basic trick of NLP and rhetoric. Repetitive actions are a key to mastering the game and the amount of repetitions is directly related to learning curve

Hide the unimportantProgressive disclosure or context awareness allows showing less important things only when they are needed.

Provide context where possible Information is interpreted depending on context. Context is a perfect reminder

Visibility

Visibility

Image RecognitionImage recognition occurs in several stages each in a separate part of the brain. Reptilian brain is responsible for recognizing shapes, movement and basic colors such as red, green, blue and yellow. This happens much faster than recognition of a complex image.

Team Fortress 2 developers consciously designed their characters for reptile brain perception. Simple shapes recognizable from any perspective and use of basic colors make sure that

characters and their team alignement can be instantly recognized

Visibility

Hick’s Law

Hick’s law states that time of making a decision is exponentially dependent on amount of

available choices

GroupingGrouping splits decision making process in several stages thus decreasing time necessary to make a decision

3 options at a time are enough to make a great game

Homeworld would never be playable without a tactical pause

Visibility

Fitts’s LawFitts’s Law states that time necessary to point an object is exponentially dependent on distance to the object and it’s size

Enemy proportions in Gears of War are designed for gameplay purpose . Shooting exaggerated bodies is easy even with gamepad and headshots are difficult but rewarding

Visibility

AffordanceAffordance is a self-explanatory purpose of an object. This is an important property that interactive game elements should possess.

How many types of items in your pockets will fit that slot? Flat road surface is a natural choice for driving without additional explanations

Visibility

Natural Mappingsnatural arrangements for the relations between controls and their movements to the outcome from such action into the world.

Guess which knob is responsible for which burner And what about this case?

Signs & Feedback

Stages of actionThere is a distinctive pattern in how human beings act. In order to ensure successful interaction, this pattern should always be kept in mind

Stages of action by Donald Norman

The World

Forming Goals

Intention to act

Sequence of actions

Execution of the action sequence

Evaluation of interpretations

Interpreting the perception

Perceiving the state of the world

Execution Evaluation

Stages of action: a simple model

Signs & Feedback

Gulf of evaluation

Evaluation of system state before and after the action is crucial for successful interaction.

Gulf of evaluation is amount of time spent on such evaluation. If the system fails to provide clear signs of its state and clear feedback on user action, the gulf of evaluation may be increased up to infinity causing frustration and anger.

Signs & Feedback

SignsSign is a display of system status. Rendering the design legible and underlining the rules of the game, the signs orientate the player in his actions.

The system is always in a specific state.

The display of this state is called Sign.

Signs must be clear so the player knows what he can do.

Signs can come from visuals, sounds or vibrations.

It should stress the “good” actions, so the player can learn from deduction and not from trial and error

Sign gives information about the system: The green cone is enemy’s sight

Taken from U-Learn Signs & Feedback presentation

Signs & Feedback

FeedbackFeedbacks are the direct answers of the game to the player’s actions. By providing information related to his performance, they help the player to play better.

Feedbacks must be clear so the player knows what he has accomplished.

Feedbacks must be immediate so player could recognize the relation between his action and feedback.

Feedbacks can come from visuals, sounds or vibrations.

It should stress not only that the action took place but also the consequences(positive or negative), thus showing the player the “good” path.

Sign gives information about the system: The green cone is enemy’s sight

Taken from U-Learn Signs & Feedback presentation

Mental Models

Mental Models

Mental model is an image of the system in human mind.

Mental models define our approach to solving problems

Understanding mental models of your audience is a key to successful design.

Power Horse tractor was designed to comply with mental models of early industrial era farmers

In Splinter Cell players can climb on some pipes, but not on others

Things that look similar should behave similarA very common design mistake is inconsistent behavior of similar objects.

Consistency and Occam's razor

Entities must not be multiplied beyond necessity. By following this simple principle you will

avoid many frustrations caused by misinterpretation of similarity. If you have only few artworks of locked doors, this may be enough for artistic diversity and easier for player to remember. Another good example is a single “use” key that initiates different actions depending on context.

Consistency

User experience and expectationsIt is important to keep in mind that users have previous experience and formed mental models. Try to be consistent with existing game design trends and the real world in order to meet user expectations.

TerminologyConsistent terminology is vital for unambiguous design. Avoid referring to gameplay-meaningful entities using different words.

BehaviorConsistency of behavior of different entities in dynamic environment makes sure that interaction is predictable and easy to learn

Visual appearanceVisual appearance is a key to recognizing things and their purpose. A fancy but ambiguous appearance is worse than simple but clear one if it relies to gameplay meaningful things

Consistency applications

Modes

Modes as the main reason of user errorsVast majority of user errors is caused by failure to recognize current mode of the system. Just remember how many errors were caused by Caps Lock. The main reason is that locus of attention is usually located on task, not on system state indicator.

Examples of modes in gamesPlayer stances, difficulty levels, user settings, camera modes

Modes as a valuable gameplay toolDisable shooting while running, allow healing while shooting, restrict movement while healing. These are all design choices that define gameplay experience and have a huge balancing potential. Make sure you are always conscious about modes in your game

Modes

Stance and action table

A vital tool for tracking modes is a table of stances and actions, with duplicate axes.

By filling all the intersections of such a table you make sure that modes are under your

control

Mode checklist table for standard First Person Shooter actions. This example contains only binary allow/restrict choices, but there are more relations to be considered like “interrupt”

and many conditions specific to your game

Further Read

The Design of Everyday ThingsThis “bible” of design written by Donald Norman is for anyone who designs anything (technical manuals, software interfaces, machinery, consumer goods, clothes) and it is also for anyone who uses the items that are designed (that is, all of us). The purpose of the book is to encourage everyone to look at design, and to see how it corresponds to how people actually use things.

The Humane Interface: New Directions for Designing Interactive Systems

Written by Jeff Raskin the designer of Apple and Apple II, this book puts forward a large

number of interface design suggestions, from obvious to radical ones. It gives a good insight on how usability can actually be measured

Human Information ProcessingA cornerstone in cognitive psychology by Peter Lindsay and Donald Norman for those who really want to dig the subject in depth.