Praxis Technology Education cheat sheet

Technology is the modification of the natural world to meet human needs and wants; it is distinct from science (explaining nature) and engineering (applying math/science to design).

Seven core technologies (ITEA/ITEEA): medical, agricultural and related biotechnologies; energy and power; information and communication; transportation; manufacturing; construction; and (in the STEL framework) the designed world categories that organize instruction.

STEL (Standards for Technological and Engineering Literacy, 2020) organizes content into 8 core disciplinary standards plus practices; the older ITEA "Standards for Technological Literacy" (2000) had 20 standards across 5 chapters (nature of technology, technology and society, design, abilities for a technological world, the designed world).

The universal systems model: input → process → output, with feedback and constraints/context; applies to organisms, organizations, and technological systems alike.

Technology assessment weighs intended benefits against unintended consequences (social, cultural, economic, environmental); technological determinism vs. social construction are contrasting views of technology-society relations.

Technological literacy = the ability to use, manage, understand, and assess technology; it has knowledge, capability, and critical-thinking/decision-making dimensions.

Evolution of the field: industrial arts (manual training, Sloyd) → industrial technology → technology education; key names include Calvin Woodward (manual training), John Dewey (experience-based learning), and Warner, who coined "technology education."

Open vs. closed systems: closed systems exchange no matter/energy/information with the environment; most real technological systems are open and require feedback control.

Constraints in design include time, money, safety, ergonomics, environmental impact, and available materials; criteria are the measurable goals a design must satisfy.

Design process (iterative, not strictly linear): define problem → research/brainstorm → specify criteria and constraints → generate alternatives → model/prototype → test and evaluate → communicate → redesign.

Criteria are desired outcomes; constraints are limits. A design matrix (weighted decision matrix) scores alternatives against weighted criteria to justify a selection.

Types of models: iconic (looks like), analogic (behaves like), symbolic/mathematical (equations, simulations); prototypes may be physical or virtual.

Brainstorming rules: defer judgment, encourage wild ideas, build on others, quantity before quality; SCAMPER and morphological analysis are structured idea-generation techniques.

Engineering design vs. technological design: engineering design emphasizes optimization under constraints using math/science; technological design emphasizes human needs and systems context-both use the same iterative cycle.

Troubleshooting vs. research/development vs. invention vs. innovation: troubleshooting fixes a malfunction, invention creates something new, innovation brings an invention to market.

Risk and failure analysis tools: failure modes and effects analysis (FMEA), fault-tree analysis, and root-cause analysis; design for manufacturability/assembly and design for the environment are concurrent-engineering strategies.

Ergonomics/anthropometrics: use percentile data (e.g., 5th-percentile female to 95th-percentile male reach) so products fit the intended user population.

Intellectual property: utility patent (new/useful process or device, ~20 years), design patent (ornamental appearance, ~15 years), trademark (brand identifier), copyright (creative expression, life + 70 years in the U.S.).

Communication system model: source/encoder → transmitter → channel (medium) → receiver/decoder → destination, plus noise and feedback.

Signal types: analog varies continuously; digital is discrete (binary). Sampling theorem (Nyquist): sample at more than twice the highest frequency to reconstruct a signal.

Bandwidth is the range of frequencies a channel carries; in digital terms it is capacity (bits per second). Shannon-Hartley: C = B log2(1 + S/N).

Modulation: AM varies amplitude, FM varies frequency; digital schemes include ASK, FSK, PSK, and QAM. Multiplexing: FDM (frequency), TDM (time), WDM (wavelength in fiber).

Transmission media: twisted pair, coaxial cable, fiber optic (total internal reflection, highest bandwidth, immune to EMI), and wireless (radio, microwave, infrared, satellite).

Networking basics: LAN vs. WAN, client-server vs. peer-to-peer, IP addressing, and the OSI seven-layer model (physical, data link, network, transport, session, presentation, application).

Graphic communication: orthographic (multiview) projection shows top/front/right views; isometric shows three faces with 120° axes; perspective uses vanishing points; scale drawings use a stated ratio.

Technical drawing standards: line types (visible/object, hidden, center, dimension, extension), title blocks, and dimensioning rules; CAD uses vector geometry, while raster graphics use pixels and resolution (dpi/ppi).

Information technologies: databases (records/fields, primary keys), spreadsheets (relative vs. absolute cell references), compression (lossless vs. lossy), and encryption for confidentiality.

Manufacturing systems: input → processing (forming, separating, combining, conditioning) → output; production types are custom/job shop, batch, mass, and continuous.

Material families: metals (ferrous/nonferrous), polymers (thermoplastic vs. thermoset), ceramics, composites, and wood; properties split into mechanical (strength, hardness, ductility) and physical (density, conductivity, thermal expansion).

Forming processes: casting (sand, die, investment), forging, rolling, extrusion, injection molding, blow molding, stamping; separating: machining (turning, milling, drilling), shearing, laser/waterjet cutting; combining: welding, brazing, soldering, adhesives, fasteners.

Conditioning processes change properties: heat treatment (annealing, hardening, tempering), alloying, and finishing (plating, painting, anodizing).

Measurement and quality: precision vs. accuracy, tolerance, and inspection; quality control vs. quality assurance; statistical process control uses control charts and ±3 sigma limits.

Lean manufacturing: the seven wastes (overproduction, waiting, transport, overprocessing, inventory, motion, defects); just-in-time, kanban, and 5S; Six Sigma targets 3.4 defects per million.

Construction project phases: design/specification → site preparation → foundation → structural framing → enclosure (roofing, siding, windows) → mechanical/electrical/plumbing (MEP) → finishes → inspection/occupancy.

Structural forces: tension, compression, shear, torsion, bending; loads are dead (static self-weight), live (occupants), and dynamic (wind, seismic); a truss triangulates for rigidity.

Building codes and zoning regulate safety, egress, and land use; green building metrics include R-value (insulation), U-factor, and LEED certification.

Energy forms: potential (gravitational PE = mgh), kinetic (KE = ½mv²), chemical, thermal, electrical, nuclear, radiant, and elastic; the law of conservation of energy states energy is neither created nor destroyed.

Power is the rate of doing work: P = W/t = Fd/t; electrical power P = VI = I²R = V²/R; efficiency = useful output ÷ total input × 100%.

Energy sources: renewable (solar, wind, hydro, geothermal, biomass, tidal) vs. nonrenewable (coal, oil, natural gas, nuclear); the U.S. electric grid uses generation, transmission (high voltage), and distribution.

Energy conversion devices: electric motor (electrical → mechanical), generator (mechanical → electrical), battery (chemical → electrical), fuel cell (chemical → electrical without combustion), turbine and internal-combustion engine.

Power transmission: mechanical (gears, belts, chains, shafts), fluid (hydraulic/pneumatic via Pascal's principle), and electrical; gear ratio = driven teeth ÷ driving teeth, and torque/speed trade off inversely.

Simple machines (lever, wheel and axle, pulley, inclined plane, wedge, screw) give mechanical advantage; ideal MA = effort arm ÷ resistance arm for a lever; efficiency = actual MA ÷ ideal MA.

Transportation systems model: vehicle, guideway/way, motive power, and control/support; modes are land, water, air, space, and intermodal.

Vehicle dynamics: traction, drag, rolling resistance, and braking; aerodynamic drag rises with the square of speed; mass transit and logistics (just-in-time) reduce cost and emissions.

Alternative energy and transportation trends: hybrid and battery-electric vehicles, regenerative braking, hydrogen fuel cells, and lifecycle (cradle-to-grave) energy analysis.

Standards alignment: STEL (2020) core standards plus the eight technology and engineering practices (e.g., systems thinking, creativity, making and doing, critical thinking, collaboration, communication, attention to ethics).

Backward design (Wiggins & McTighe): identify desired results → determine acceptable evidence → plan learning experiences; write measurable objectives with Bloom's verbs.

STEM integration connects science, technology, engineering, and mathematics through authentic problems; engineering design is the integrative context, not an add-on activity.

Lab safety and liability: documented safety instruction, signed safety contracts, PPE, machine guarding, lockout/tagout, and supervision duty; negligence requires duty, breach, causation, and injury.

Assessment types: formative (ongoing feedback) vs. summative (end of unit); performance and portfolio assessments suit design work; rubrics make criteria explicit.

Instructional strategies: project-based and problem-based learning, design briefs, cooperative learning, differentiated instruction, and universal design for learning (UDL).

Professional organizations and development: ITEEA, its journals (Technology and Engineering Teacher), conferences, and state associations; continuing education maintains certification/licensure.

Equity and inclusion: broaden participation of underrepresented groups, ensure accessible tools and materials, and avoid bias in examples and project requirements.

Legal/ethical duties: FERPA (student records privacy), copyright/fair use for classroom materials, and accurate reporting of student achievement; teachers serve as role models for academic integrity.