Search every subject world, from Preschool to Grade 12. The first five courses of every subject path are free.
33 courses
Computers & Digital Literacy · Every grade
A hands-on start for anyone new to computers, tablets or PlayOwl. Children really point, click, tap, drag, scroll, zoom and type, open and close tabs and windows, search on a pretend web, and take a tour of PlayOwl, all inside safe practice screens. It works with a mouse, a touch screen or a keyboard.
Computers & Digital Literacy · Grade 9
Learners sort machine-learning requests into classification, regression and clustering, read a dataset as examples, features and a label, and learn to ask what a label really measures. They then frame projects before any model exists: the decision, the people affected, the cost of each error, a success criterion and a baseline. The course ends by deciding when a simple rule, more data or human judgment is the better choice.
Computers & Digital Literacy · Grade 9
Defensive security starts with understanding what you are protecting. Learners inventory the assets of a fictional public library, describe harm with confidentiality, integrity and availability, separate threats from vulnerabilities and controls, rate risks with a likelihood-times-impact matrix, and build a first threat model for a fictional food pantry's volunteer sign-up website.
Computers & Digital Literacy · Grade 9
Learners turn categories and text into numbers with one-hot encoding and word counts, and rescale numeric features with min-max scaling using training-data limits. They then examine how the data a model learns from can mislead it: sampling variability versus representation bias (with a sampling simulation), and measurement, label and historical bias in fictional datasets, each paired with a mitigation.
Computers & Digital Literacy · Grade 9
Learners separate identification, authentication, authorization and accountability, compare authentication factors and multi-factor methods, calculate how the number of possible codes grows with length, and apply least privilege, role-based access and separation of duties to fictional organizations. The course ends with the access lifecycle: joiners, movers, leavers and a real access review.
Computers & Digital Literacy · Grade 9
Using only toy examples, learners build the vocabulary of cryptography with a shift cipher and see why its tiny key space makes it useless for real secrets. They compare shared-key and public-key encryption, explore hashing with a deliberately weak toy hash, and finish with digital signatures, certificates, what the browser padlock really means, and good key-management habits.
Computers & Digital Literacy · Grade 9
Learners build three simple models entirely by hand on small fictional datasets: a one-feature threshold learned by counting the errors of each candidate cutoff, a two-level decision tree grown by choosing the split with the fewest errors, and a k-nearest-neighbors classifier using Euclidean distance and a majority vote. They then compare hand-written rules with learned models on transparency, maintenance, adaptability and data needs.
Computers & Digital Literacy · Grade 9
In a toy model of a library network, learners split a flat network into zones, evaluate firewall rule tables where the first matching rule wins and everything else is denied, read fictional sign-in and connection logs for warning signs, and choose hardening controls such as replacing default passwords and closing internet-facing admin pages. Everything happens on paper-style tables; no real networks are touched.
Computers & Digital Literacy · Grade 9
Learners split data into training, validation and test sets and compute the counts for common splits. They use validation results to choose settings such as k and tree depth, read the overfitting signature in training and validation error, and learn why the test set is used only once. They then hunt for data leakage in fictional project logs and choose stratified, time-based or group splits when a simple random split would mislead.
Computers & Digital Literacy · Grade 9
Learners evaluate a fictional leak-detection model the way practitioners do: they build confusion matrices and compute accuracy, precision, recall, specificity and F1 with the real formulas, compare the model with a majority-class baseline, and measure regression error with mean absolute error. They then choose a decision threshold from the costs of each error type and break errors down by subgroup and by error type to recommend next steps.
Computers & Digital Literacy · Grade 9
Learners look at a fictional food pantry's volunteer app from the builder's side. They validate untrusted input with allowlists on the server, apply secure-by-design principles such as least privilege, safe failure and careful error messages, handle data responsibly from collection to deletion, and turn security requirements into concrete test cases.
Computers & Digital Literacy · Grade 9
Learners explain models globally and locally: they compute permutation feature importance as the drop in performance when a feature is scrambled, and write counterfactual explanations for individual decisions, judging whether they are actionable. They then study what explanations cannot tell us (correlation is not causation; out-of-distribution inputs) and design human oversight with review queues, appeals and override logs that counter automation bias.
Computers & Digital Literacy · Grade 9
Learners study how social engineering exploits ordinary human responses such as urgency, authority and helpfulness, then practice reading sender addresses and web addresses to find the domain that really controls a link. They learn to verify through a separate, known channel, respond calmly after a mistake, and design organizational defenses that cover email, phone, text messages, QR codes and in-person tricks. All messages are fictional and use reserved example domains.
Computers & Digital Literacy · Grade 9
Learners follow a fictional food pantry through a realistic account-compromise incident, from a lookalike email to a copied volunteer list. They learn the phases and roles of incident response, separate events from incidents and rate severity, build a timeline from several logs while preserving evidence, and practice clear, factual communication and a blameless post-incident review with owned action items.
Computers & Digital Literacy · Grade 9
Learners apply data minimization, purpose limitation and meaningful consent to fictional data plans, then measure re-identification risk by counting how many records share the same quasi-identifiers before and after generalization, suppression and aggregation. They read and write model cards and dataset datasheets, and plan governance across a model's life: impact assessment, named roles, monitoring for drift, and people's rights to access and correct their data.
Computers & Digital Literacy · Grade 9
The elective's capstone. Learners carry out a complete, strictly defensive security review of a fictional bike co-op: they agree written permission and scope, gather evidence from documents, settings and interviews with a checklist, rate and prioritize findings, write specific recommendations with owners and dates, and present a clear report with a plain-language executive summary and a follow-up plan.
Computers & Digital Literacy · Grade 9
Learners carry out a complete, small modeling project on a fictional library dataset: they frame the problem and fix a success criterion, check the data for leakage, minimization and quality problems, make a time-based split, compute baselines, build and choose between a threshold model and a small decision tree on validation data, evaluate the chosen model once on the test set, analyze errors by subgroup, and write a model card that a teacher reviews against a rubric.
Computers & Digital Literacy · Grade 10
Learners move fluently between binary, decimal and hexadecimal, reason about the limits of fixed-width storage and what happens on overflow, and calculate the uncompressed size of images and audio from their parameters. They then compress data by hand with run-length encoding, measure compression ratios, and decide when lossless or lossy compression is the right tool.
Computers & Digital Literacy · Grade 10
Networks lose, damage and delay data all the time, yet messages still arrive intact. Learners analyze redundant paths and single points of failure, trace how acknowledgments, timeouts and retransmission repair packet loss, detect errors with a parity bit and a toy checksum, and calculate transfer times from latency, throughput, bottlenecks and header overhead.
Computers & Digital Literacy · Grade 10
Learners take a web page apart: the requests that assemble it, the parts of its URL, the HTML that gives it structure and the CSS that styles it. They then evaluate pages the way assistive technology experiences them, checking alt text, link text, form labels, contrast ratios and keyboard focus, and recommend fixes with reasons.
Computers & Digital Literacy · Grade 10
Learners follow primary and foreign keys across related tables, model many-to-many relationships with junction tables, and see how storing the same fact in many places causes update, insertion and deletion anomalies that normalization prevents. They read SQL-like queries with SELECT, WHERE and ORDER BY and predict their results, then compare metadata, folders and tags as ways to organize and find information.
Computers & Digital Literacy · Grade 10
Through fictional, safe scenarios, learners classify incidents by the confidentiality, integrity and availability they harm, separate threats from vulnerabilities, and score risks with a likelihood × impact matrix. They triage fictional phishing messages and lookalike links, then plan layered defenses: patching priorities, backups that survive ransomware, and clear incident reports. Everything is defensive: recognition, prevention, detection, response and recovery.
Computers & Digital Literacy · Grade 10
Learners look inside predictive AI systems through small fictional datasets: features and labels, a rule learned from training examples, and why models must be judged on separate test data. They diagnose overfitting, distribution shift and proxy features, discover with simple counts why accuracy misleads when events are rare, and write the limitations a responsible team should document.
Computers & Digital Literacy · Grade 10
Following a youth council team writing a grant proposal, learners set sharing permissions and link settings by least privilege, use version history, naming conventions and changelogs to track and restore work, and resolve conflicting edits by comparing each version with the common original. They finish by defining team roles and the asynchronous communication norms that keep shared work moving.
Computers & Digital Literacy · Grade 10
In this project course, learners act as consultants for the Cedar Valley Tool Library, which lends tools to residents and has outgrown its paper sign-up sheets. They analyze the system's people, processes, data, hardware and software, write testable functional and non-functional requirements, trace how data flows and where protections belong, and then compare two fictional products with weighted criteria before writing a justified recommendation.
Computers & Digital Literacy · Grade 11
Before trusting any number, learners examine how its data were collected. They separate populations, sampling frames and samples, compare random, stratified, convenience and voluntary-response sampling, diagnose sampling, nonresponse and measurement bias in fictional Cedar Valley studies, use a sampling simulation to separate random variability from bias, and ask who is missing from app logs and sensor data and what informed consent requires.
Computers & Digital Literacy · Grade 11
Learners migrate a messy shared spreadsheet, the Cedar Valley Community Garden's volunteer sheet, into a relational design step by step. They find the entities hidden in a flat sheet and the anomalies its repeated facts cause, choose stable primary keys, make values atomic, split tables so each fact is stored once, link them with foreign keys, compare spreadsheet lookups with database joins, check referential integrity while loading, and document the result in a data dictionary.
Computers & Digital Literacy · Grade 11
Learners answer real questions from Cedar Valley Bike Share's trip data by predicting exactly what SQL-like queries return: filters that combine AND, OR and NOT with parentheses, aggregates with COUNT, SUM, AVG and GROUP BY, and inner joins that silently drop unmatched rows. They then turn a result into communication: choosing a visualization that fits the result's shape and writing a precise headline with annotation, honest axes and caveats.
Computers & Digital Literacy · Grade 11
Learners act as the volunteer IT team for the fictional Cedar Valley Public Library. They split a flat network into guest, staff, device and server segments, apply toy firewall rule tables where the first matching rule wins and everything else is denied, read fictional sign-in logs for warning signs such as bursts of failed logins, and harden systems through secure configuration, patch management, least privilege and the zero-trust idea. Everything is defensive: recognizing, preventing, detecting and responding.
Computers & Digital Literacy · Grade 11
A vendor says its leak-detection model for Cedar Valley's water meters is '97% accurate'. Learners find out what that does and does not mean. They build confusion matrices, compute accuracy, precision and recall with the real formulas, see how rare positives make accuracy misleading, trace how a decision threshold trades false positives for false negatives, choose metrics by the cost of each error, and evaluate fairly with separate test data and subgroup results.
Computers & Digital Literacy · Grade 11
Learners review the design of Spokewise, the fictional Cedar Valley bike share's new app, and a student team's study-timer app. They apply privacy by design (data minimization, purpose limitation, retention limits, protective defaults and meaningful consent), recognize and redesign deceptive design patterns, distinguish copyright, patents, trademarks and trade secrets, compare permissive and copyleft open-source licenses as concepts, and reason through design decisions with stakeholders, consequences and rights. All legal content is general information, not legal advice.
Computers & Digital Literacy · Grade 11
This advanced course follows the Cedar Valley Library's design team as it tests and repairs its new study-room booking page. Learners compute usability metrics (task success rate, time on task, error rate and post-task ease ratings), plan an ethical, inclusive test with disabled participants, informed consent and non-leading tasks, audit accessibility through the keyboard path, accessible names, contrast ratios, captions and reflow, and then prioritize findings by severity and frequency before retesting.
Computers & Digital Literacy · Grade 11
In this project course, a student team investigates why Cedar Valley High's Wi-Fi slows to a crawl at lunch. Learners turn a complaint into a testable question with competing hypotheses, choose data sources (access-point logs, latency measurements, link usage, a survey, a schedule) with permission and privacy safeguards, analyze fair comparisons across time, place and days, write claim–evidence–reasoning statements that match the strength of the evidence, name confounders and limitations, and write a full investigation report with evidence-based recommendations.
