I don’t read book summaries. Neither should you. The following are mostly notes to myself for later reference, and are my interpretations.

I recommend this book to folks who have interest in hardware design, have fiddled with hardware design in some way or the other. It may be too trivial or basic for professional industrial product designers.

It's a long one, so gear up. I am going to use these as written or printed notes as flashcards and keep them at our working desks to serve as regular reminders. Although the book is linear in nature with 101 tips, I have categorised them:

Observation practices

Design is a physical act.
All design is done in relation to the body, so use your body to design. Even virtual/digital products engage the body through visual interface, touch screens, and pointing devices. Bias the design process toward action, using your own body as a tool. Act out the user experience. Pretend to push the button. Operate the control screen. Use the RO to fill glasses, flasks, cups and observe the tiniest of the problems and document them.

The apparent problem probably isn’t the real problem.
E.g. you might be asked to design a better pooper-scooper because people aren’t picking up after their dogs. A reasonable assumption might be that this is because people don’t want to risk touching excrement. But research might reveal that owners simply forget to take bags on their walks. A new scooper would not solve this problem, so the problem must be reframed as one of the placing bags where dog walkers need them — perhaps within the leash handle, in a dispenser at the dog park, or at key locations on city streets.

A need is a verb. People don't need a…
Vase; they need to display and enjoy flowers.
Teacup; they need to consume tea.
Chair; they need to experience rest.
Lamp; they need lighting.
Humidifier; they need to humidify the air.
Water bottle; they need to drink liquid while on the move.
Parking garage; they need to store their car.
Library ladder; they need to access information.

An insight is more than an observation.
An observation is the perception of an objective fact or condition. An awareness is an observation that continues to reside in the mind, carrying with it an expectation of significance. An insight is the recognition of the deep significance of something one already knew. An insight is revelatory and holistic; it organises complex relationships or ambiguous phenomena in a simple, clarifying way.

Observation: People move public chairs (e.g. chair by the dining table) before sitting in them.
Awareness: To think that this behaviour could be significant in some way.
Insight: Moving chair is how people assert choice and control, and create defensible space!

All products move.
Portability is critical, even for products that remain stationary in ordinary use. A large, heavy printer may sit in the same place for years, but indentations built into the sides will be appreciated when it is set up and on the rare occasions when it must be moved.
A home refrigerator has wheels on the bottom and a mattress has handles on the side, even though they will remain stationary for most or all of their lives. A product moves again when its useful life is complete and it is disassembled, thrown away, or recycled.

Understand your world in numbers.
Make a habit of guessing the dimensions of objects in your environment, then measure them to see how close you were. 

Measure the dimensions and spacing of controls and buttons. 
Measure your eye height in a seated position, and the ratio of television screen size to preferred viewing distance.
Measure the spaces between parked cars and between icons on a phone screen.
Measure the size of a soda can, cell phone, dollar bill, house key, paperback book, air conditioner, dinner plate, and Shih Tzu.
Handspan (pinky to thumb wide open) = 7” - 9”
Chair seat above floor = 18”
Table surface above floor = 30”
11 sticky notes = 1mm

Designing

Make your ideas mobile.
Being creative isn’t just coming up with new ideas; perhaps more often it’s connecting ideas. The more a designer can freely move among ideas, the more likely important connections will materialise. Posting your drawings, research notes, lists, and brainstorms on a wall or whiteboard makes multiple ideas visible at once, maximising the likelihood of identifying useful, novel connections.
If connections aren’t evident, mush the materials around. Rearrange, cluster, organise, combine, uncombine, manipulate, and reinterpret them to generate new patterns, ideas, user scenarios, and narrative sequences. Invite others into the process to multiply opportunities.

Design needs language.
Each week, write a design statement — a paragraph explaining your understanding of the users, the problem, and your approach. Don’t record only fully formed ideas; use your writing as a tool for thinking and discovering, and for refining old understandings you may have thought settled. Don’t hesitate to spend an hour on a single paragraph if needed.
When you encounter major obstacles in the design process or are stymied by a looming decision, review an accumulation of design statements to see if their evolution suggests a natural next step.

Use your feet.
Many products need feet to help them stand level, but feet can be functional in other ways. They can provide grip, prevent scratching of the product bottom, absorb impacts, protect the surface on which the product sits, improve performance, make visual sense of the form, and even assist in its manufacture.

Give the user a fair chance to figure it out.
Providing users an opportunity to discover a feature is different from hiding a feature. Annoyance will likely result when the user is both visually and physically barred from easy or intuitive access — for example, when a power button is located on the back of a speaker.
But a pleasant aha! may result when the user has an opportunity to discover a feature that is not initially apparent but is nonetheless accessible, such as a product logo that turns out to be the power button. Once the users recognise it, there is no further barrier to use. They may think, “Why didn’t I see this before?” and enjoy reliving their original aha! on subsequent uses.

Form follows function… and much less.
In a typical mixer/grinder, tapered base eases release from manufacturing mold. facilitates stacking of parts, provides visual and physical stability, and tilts interface screen toward user. Rounded corners are pleasant to touch, they are structurally stronger than right-angle corners, and provide pleasing visual “softness.”

Match your craft to your confidence.
Give a drawing, prototype, or other study only as much time, effort, and investment as are needed to generate feedback on the issues relevant at the stage of development. Detail, exactitude, and craft should represent the confidence the design deserves, and no more.

Draw as a designer, not as an artist

Draw efficiently, not expressively. Most drawings should be quick, clear visitations of ideas, not precious pieces of art.

Draw symbolically, not realistically. Omit peripheral details to bring focus to the message you want the viewer to receive.

Don’t strive for a signature drawing style. Let your personal style develop organically over time.

Draw fast. The computer is for detailed renderings. In hand sketching, rapid visualisation is most important; it communicates ideas in conversation.

Random hypothesis: Beauty is universal.
Objects considered beautiful by one culture are almost always considered beautiful by other cultures. Taj Mahal, Agra. Yet the objects produced by any one culture are often very different from those made by another culture. Some cultures produce sensuous, earthy forms; others value the austere and high tech.  Some value decorative embellishment, while others prefer unadorned surfaces. Some emphasise rectilinear shapes, others the curvilinear.

If cultures hold similar ideas of beauty, why do such differences exist? It is because other factors — the display of power or prestige, historical references, physical context, and more — also shape how things look, and cultures value these factors in different proportion. The aesthetic outcomes are very different, even though notions of beauty are very similar.

Go partial Monty.
If a product contains complex components or innovative technology, consider making it visible from the outside to express high performance. But keep it subtle. Give a small hint rather than go full Monty. Brake callipers.

Light tones amplify details. Dark tones amplify silhouette.
Lighter tones naturally reveal variations in light and shadow, suiting them to objects whose contours and details are meant to be appreciated, such as classical marble statues. It is more difficult to perceive variations and details within darker tones, suiting them to objects that are not meant to be noticed, such as staplers, mouse pads, and living room electronics.
An exception is the automobile, because a glossy, dark surface in a bright outdoor setting acts as a mirror. The many reflections on a dark car make its form look more complex and contoured than the same model of car in white.

White is practical. Black is sophisticated. Metal is professional.
White is a natural choice for products in which purity, cleanliness, and utility are valued, making it the default colour for laundry and kitchen appliances (“white goods”). 
Black tends to imply sophistication, especially for personal products such as leather goods. This is in part because it obscures surface details, lending an air of mystery.
Metal finishes such as brushed stainless steel tend to project a professional vibe. Homeowners wishing to convey professional-level capability within their homes are increasingly favouring it for new appliances.

Satin is more slippery than gloss.
Rough surfaces tend to have more “grip” than smooth surfaces, making our hands and feet more steady and secure. But when smoothness increases beyond a certain point, this ceases to be the case. Gloss, the smoothest possible finish, has more grip than a satin finish.
In guitar, body is gloss finish for maximum grip, back of the neck has satin finish for easy hand movement, and headstock has gloss finish.

Seating principles.
The lower you sit, the longer you sit, and the greater the role of comfort.

Backrests and armrests imply greater commitment; e.g., a backless bench implies shorter-term use than a dining chair or lounger.

Right angles inhibit comfort. A seating surface should usually be lower at the rear edge than at the front, producing a tilt upto to 5° from horizontal. A backrest should slope backward 5° to 15°.

Swivel indicates performance/ utility, e.g., a task chair, barstool.

Move upright tends to suggest greater social engagement. Greater reclination suggests greater privacy. A recliner in a public space, such as a beach or movie theatre, exhibits an atypical mixture of private posture and public experience.

Table height = elbow height of a seated person.

Did what was supposed to happen happen?
Some products provide automatic feedback: A vacuum cleaner communicates that it has been turned on or off with sound. A vibration may be more effective than a visual cue for indicating a cell phone has been placed in silent mode. In a busy visual context, a computer screen or automobile dashboard an auditory cue may be most readily noticed. Physical switch vs. smartphone example:

Feeling of turning on a switch - tactile, haptic feedback on phone, Seeing the switch go down - visual feedback on screen. Sound of switch click - tone coming from phone.

Draw as a designer, not as an artist.
Draw efficiently, not expressively. Most drawings should be quick, clear visitations of ideas, not precious pieces of art. Draw symbolically, not realistically. Omit peripheral details to bring focus to the message you want the viewer to receive. Don’t strive for a signature drawing style. Let your personal style develop organically over time. Draw fast. The computer is for detailed renderings. In hand sketching, rapid visualisation is most important; it communicates ideas in conversation.

Use perspective drawings for expression. Use orthographic drawings for investigation.
Perspective sketches are effective for capturing an overall idea quickly, and may make a strong impression by showing a product’s relationship to space or its use context. But orthographic drawings (two-dimensional plans, sections, and elevations) are much more likely to help you evolve an idea. Their inherent exactness, especially when drawn full size, compels a designer to investigate and pursue specific decisions on size, scale, proportion, and detail.

Explore the product personality early.

• When someone encounters the product, what feelings should it evoke?

• What senses will be engaged?

• How should they feel when they see, touch, or use it?

• What fond experiences might it lead them to recall?

• What is the product’s inner character?

• Should it be expressive, calm, dependable, mysterious, lighthearted, aggressive, self-contained, fancy, retro, clunky, or understated?

• What scale and proportion will feel right?

• What colours, textures, shapes, and patterns are suggested?

• What sizes and types of controls, buttons, hardware, and other interaction points are called for?

• Is it traditional or cutting edge?

• What values will the user look for — safety, solidity, high-fashion, femininity, invisibility, technological innovation?

• What metaphors help describe the experience of using the product?

• What will stand out in repeated uses?

• How might the satisfied user describe the product to others?

• What is the personality of the intended users, and what identity keys can be borrowed from them to make it feel right?

Make it look like what it does
A well-designed product communicates how it is to be engaged through affordances — cues as to how to hold, use, or otherwise interact with it. Affordances build on a user’s mental models of the action to be performed.
Rotate the knob and pull to open the door.
Grasp a teapot by the handle and pour from the spout on the opposite side.
Flip a switch up to turn on and down to turn off.
Affordances often build on users’ past experiences. When soda cans changed from a detachable to an attached latch, consumers had to relearn how to open a can, but they still knew where to open it. Identifying affordances for a global product can be challenging, as they may vary across cultures. Squat-style toilets in China, for example, are not typically understood by Westerners.

10% thicker is 33% stronger.
Consumers tend to perceive material stiffness as an indicator of overall product quality. For most materials, a modest 10% increase in thickness will yield an impressive one-third increase in strength and stiffness, reducing twisting, housing squeaks, “oil canning,” and other structural problems and annoyances.

Recognise the gravity of the situation.
We know intuitively that an object that is narrower at the top than the bottom has a lower center of gravity and is less likely to tip than an untapered object. Our sense of visual stability derives from this understanding, as even objects that are not vulnerable to tipping, such as a traditional lampshade, are often more visually satisfying when made narrower at the top.
A disposable coffee cup may seem to overlook gravity in that it is wider at the top, which facilitates pouring into it, drinking from it, and stacking it. This makes it more prone to tipping than is desirable. Yet gravity still drives the cup’s form: when you hold it, gravity pulls the cup down into semicircle formed by your thumb and fingers. If the cup were wider at the bottom, it would be very difficult to hold.

A product has a right weight.
Heaviness works in: furniture (high-quality), frying pan, dress-shoe with heavy-sole (high quality), razors at home (last long), stationary stapler (hefty), fountain pen.

Lightness works in: Laptops, headphones (efficiency), athletic shoe, portable stapler, disposable pen, disposable razors (for travel)

A box is more than a box.
A product housing is made of at least two parts. The parting line that separates them may be located by purely practical concerns, such as internal workings, manufacturing ease, or structural strength. But other locations can communicate a message.

Placed on the bottom of a product, a parting line is concealed during ordinary use, communicating solidity — a desirable trait in a stationary product.

Placing it at midpoint on the sides is neutral or generic, but may provide an opportunity to visually enliven the product by using different colours or finishes on the two housing pieces.

Buttons.
Flush buttons have minimal physical presence and usually require direct visual access. They suit functions used occasionally, such as submenu programming. They effectively preserve the purity of a product’s form, but are difficult to find by feel.

Extruded buttons are raised slightly; one can find them by feel. They often suit common operations, such as “Scan” or “Paper feed.” A particularly high extrusion may be appropriate for the primary operation of a device, e.g., “Puree” on a blender or “Record” on a video camera.

Recessed buttons suit special, seldom-used functions whose accidental activation could be catastrophic. They are often made deliberately difficult to press, such that special physical effort must be made. Activating “Reset” on a Wi-Fi router, for example, may require the insertion of a pen tip or paper clip.

Paint is a last resort.
Products whose finish reveals, rather than conceals, the material’s true colour tend to command higher value and age better than products with a painted surface. Paints are effective cover for cheap materials, but it may also advertise that the underlying material is cheap: if it isn’t cheap, why is it hidden?

In watches natural colour is enhanced by surface treatment: polishing, sandblasting, clear coating.

In string instruments, colour is infused into material: dyeing or staining, mixing pigments into material during casting.

In hooks, layer of colour is technically bonded: chemical, electrostatic, electrolytic, or thermal process.

Indicate the function; don’t just show the form.

• Draw the hinge in motion, not just the hinge.

• Show the drawer being opened, not just the drawer.

• Show the knob being turned, the lid being unscrewed, and the flap swinging open.

• Show a hand operating a handheld device or flipping a switch.

• Show the massager vibrating.

• Draw the chair reclining, the table being unfolded, and the tent being erected.

• Show the lamp turning on and off.

Make one thing more important than everything else.
One clear idea — a design element, quality, shape, function, form, material, colour, or feature — should triumph over all others and embody a product’s core narrative. Whenever anyone describes the product to the uninitiated, the primary design component should come up.

• Apple laptop: monochromatic elegance

• Breuer chair: Continuous steel tubing

• Volkswagen Beetle: ladybug shape

• Arco lamp: unique scale and proportion extend boundary of floor lamps to that of suspension lamps

Contextual simplicity calls for hidden complexity.
Craighton Berman Studio’s Stool No. 1 appears to be made from a single, long piece of bent rod. However, this would require a 30’ long piece of metal and a cumbersome manufacturing process. Instead, the legs are made from four separate but identical parts that are joined under the seat.

An inexperienced designer may resent such manipulations for “polluting” a design concept. The aware designer understands that conceptual or narrative simplicity rarely means literal simplicity.

Pollution is a design flaw.
Natural, nonpetroleum-based materials may seem inherently better for the environment. But many items that seem environmentally friendly, from sugar packets to paper cups, are coated with a thin plastic layer, making difficult and even impossible to recycle.

A plastic cup made from a single synthetic material, however, such as polyethylene or polypropylene, can be easily recycled.

What to build/ business

A $25 teakettle needs to boil water, whistle, be dependable, and look appealing. A $900 kettle mostly needs to be beautiful.
The cost of a tangible function tends to be apparent in a market economy. A $10 Casio watch, for example, is almost purely functional, thereby establishing that telling time has a utility value of perhaps $9.
A Patek Philippe watch can cost $80,000, suggesting that almost all of its value is sign value — the status it grants its wearer. Prestige, being an abstract quality, lacks a clear price standard.

Identify the experience, not just the product.
Every product has one or more core experiences that transcend the product itself. 
In a Mountain bike, the core experience/product is Biking. The secondary product/ experience could be exploring the outdoors, embracing physical challenge, escaping workday structure, rain gear, emergency tools, and high-nutrition snacks.
With Coffee, the core experience/ product is drinking coffee. The secondary product/ experience could be having food with coffee, listening to music while having a coffee break, buy coffee beans, buy a tumbler for coffee on-the-go, or buy a coffee mug.
Identifying the core experience clarifies users’ motivations and needs. Secondary products may build additional interest in the core experience and increase users’ reliance on the product brand.

Cleverness is unexpected efficiency.
Cleverness prompts delight, but it is fundamentally is functional, not emotional, quality. It engages and rewards by offering a solution or detail that is multifaceted but unexpectedly simple. It solves a core functional problem while adding at least one more element of functional value.
A gimmick may lend initial delight, but will likely fail in the longer run because it adds little or nothing of functional value. Gimmickry asks to be noticed; cleverness does not ask to be noticed but is noticed anyway.

Retail = (BOM + labour) x 4
A bill of materials is a detailed list of parts needed to manufacture a product, from motor assemblies to tiny screws. A BOM lists part names, specifications such as dimensions and colours, and their prices. A rough estimate for the retail price of a product, assuming design and development costs are covered within the profit margin, is four times the manufacturing cost.

Design the user experience through time.
Sneakers:

• First few uses: emotional (appearance, cool factor, delightful interaction)

• Extended use: rational (durability, reliability, comfort)

• Prolonged use: emotional 2.0 (life context, familiarity, inner character)

In the first several uses of a product, users may be smitten. Take advantage of their attention by creating early “wow” moments. 

• Electronic products can showcase their personality through lights, sounds, and interface details.

• A washing machine might display helpful tips and play a happy tune to celebrate the first wash.

For physical products, use striking colour combinations, precise corner details, and interesting joinery to reward the new user’s infatuated gaze. For physical objects, durability and reliability provide the ultimate longtime rewards.

Miscellaneous

A playful object doesn’t have to be an object for play.
Playful forms work best when introduced into ordinary, familiar products, such as those commonly found in the home and office. This is because their function is well understood, limiting the potential for confusion.
When seeking playfulness, see if the product’s inherent form suggests anything. References should be whimsical, not cute or kitschy. Simplify the form to avoid literalism: most people will be more comfortable using a handsaw that vaguely suggests a cat than using a literally rendered cat whose ability to cut wood is not evident in its form. Use natural features and details in the referenced object, such as eyes and limbs, to support the product’s functions. Finally, use high-quality materials to assure the user that the product isn’t a gimmicky throwaway.

Software in unavoidably imperfect.
Consumers expect physical products to be perfect or near perfect. But software users are comparatively accepting of imperfections. They may be annoyed by bugs and shortcomings, but they will work around them until an update is issued. At that point, they likely will expect — and receive — fresh features in addition to fixes. This will result in a new round of imperfections that they will accept and work around.
A software company, therefore, has little incentive to work out every bug in a product before putting it on sale. If it were to take more time to do so, consumers would not wait, but would buy an imperfect, readily available product from a competitor.

How to draw a straight line
Use a felt pen. If drawing long lines, use a thicker pen for greater presence, as a more prominent line is easier to evaluate.

Draw individual lines slowly. If you stroke a line too quickly, you will have less control over direction and straightness.

Move your entire arm rather than pivot from the elbow. Drag your drawing hand across the page if it adds traction.

Slightly wiggle lines are okay as long as the overall line is straight and not an arc.

Rotate the drawing medium if it makes it easier to draw straight lines.

Don’t “flick” the line. Give the start and end a hard stop.

Repeat until you are able to draw consistently straight lines with a clear beginning and end. This will take at least a few weeks of moderate training to internalise into muscle memory.

Screw heads.
Slotted (straight) screw head suggests retro “throwback,” but may look generic. Allen/hexagonal screw head suggests ruggedness. Torx/star screw head are small & suggests precision. Phillips/cross screw heads are practical, but may look generic.

Use a patent to protect your business interest, not your emotional interest.
Creations are personal; protecting them through registration with the US Patent and Trademark Office might seem like a way to safeguard one’s emotional investment in them. But the real benefit of intellectual property (IP) protection is economic.

A utility patent grants a creator legal ownership of a functional improvement to a product, process, technology, or mechanism. It can be costly, but if granted by the USPTO the patent holder may legally prevent competitors from copying or using the improvement, charge or license others for its use, or sell it outright.

A design patent protects aesthetic or ornamental elements rather than function. It is easier to obtain than a utility patent but may be difficult to protect, as competitors can market very similar designs.

A provisional patent temporarily prevents others from using a creation for which one has filed a patent application, pending approval or rejection by the USPTO.

• TM: Trademark, not registered; may or may not be protectable

• Nondisclosure agreement: protects ideas shown to potential partners and investors

• U.S. Registered Trademark: may be valid indefinitely

• Design patent: 15 years

• Copyright: USU. valid for 50-70 years after death of creator

• Utility patent: 20 years

Injection molding.
Mold/part shape: A part needs to slide out of its mold after casting. This requires that its sides have a draft angle of at least 1°. Additionally, complex shapes with “undercuts” can become trapped in a mold. Side ejection may be possible, but is expensive. Making a part in two pieces will often solve this problem.

Mold or die material: Heat-treated steel “tooling” suits high-volume production, up to 100,000 cycles. Aluminum is less expensive but will last only a few thousand cycles. It is often used for pre-production prototypes that closely resemble the final product.

Production speed: Manufacturing can be accelerated with aluminum tooling, which cools faster but is less durable. Two- or three-cavity molds will produce more units per cycle, increasing initial tooling cost but lowering the cost of each part.

Plastic is a property, not a material.
Plastic describes any material whose shape can be easily changed or molded. Typically, a raw plastic material is shaped in a heated state, then cooled to create a hard or semi-hard product. The materials we most often refer to as plastic are made from polymers, long chains of carbon and other atoms sourced from petrochemicals. However, plants are being increasingly used as a source. At the end of their service life, bioplastics can be consumed by bacteria rather than thrown away.