Every teacher knows they’re supposed to check for understanding. Part of our job is to figure out whether students have learned what we taught them and adjust our teaching based on that information.

In my experience, the most common tools teachers use to check for understanding are daily exit tickets, weekly quizzes, and periodic interim assessments. Those are all fine tools. But none help me make minute-to-minute adjustments, figuring out within a single lesson what students have learned, what they haven’t, and helping me adjust my teaching on the fly.

In a lot of classrooms, any on-the-fly, minute-to-minute adjustments that happen are based on calling on a single student. Ask a question, one student answers, and decide whether to keep moving or spend more time on a topic based on that one answer. That single data point leads to both false positives and false negatives.

Lots of students get confused in math class. Or at least they are in mine, maybe you’re a better teacher than me. If I don’t figure out that someone is confused until the end of class because I’m only calling on one student at a time, I’m missing opportunities to help students.

I think adjusting within a lesson, rather than between lessons, is one of the most powerful things I can do as a teacher. So I need tools to do that. Ideally, those tools do a few things:

• They get a large sample of the class. I don’t want to ask one student and assume the rest of the class is in the same place.

• They are adaptable to different content and different places in a lesson.

• They don’t require much prep, and can ideally be improvised when necessary.

• They don’t take too much time.

I have two favorite tools I use to check for understanding that, together, meet these needs.

Mini Whiteboards

Here’s something I do pretty much every class. I have students grab a mini whiteboard, a marker, and a small rag to erase with. I write a question on the board. Students write their answers on their mini whiteboard, then flip it upside down so their partner isn’t tempted to copy. Then, on my signal, all students hold up their whiteboards for me to see.

This is my number one teaching move. Here are a bunch of advantages of this check for understanding:

• Mini whiteboards are great for any topic where we might be ready to move on, but if students are shaky I might want to do a quick review and then ask a few more questions. I can adjust the questions as necessary, and we can do as much or as little practice as students need.

• They’re also great for prerequisite knowledge checks. If there’s something I want to make sure students know for the day’s lesson, I check it at the beginning using mini whiteboards. I can add some more practice if students need it, and move on if they don’t.

• They’re helpful for structuring retrieval practice. I can cycle through a few different review questions. This gives me a sense of which skills students are solid on, and which skills are shaky. I give my students a lot of retrieval practice on paper as well, but I want to make sure students are solid on a skill before tossing those problems into the retrieval practice mix. Mini whiteboards are a great way to gauge this.

• Mini whiteboards are a great tool to gauge student understanding right before independent practice. I can ask a question, jot down the students who get it wrong, and follow up with them individually as students start independent work.

• I can also use mini whiteboards to gauge how far student understanding goes in a topic. I can start with a simple question, and ask gradually harder questions to figure out where students get tripped up.

• Mini whiteboards are great for explanations. If I want students to explain something, I have them write their explanation on mini whiteboards and follow the same routine above. The difference is, I can’t read a full class of explanations as quickly as I can check the answer to an equation. For this, I choose a few indicator students. Think of three students, roughly at the 10th, 30th, and 50th percentiles of your class. Read at least those three when students hold up their boards, maybe read a few more, and use that data to decide what to do next.

• Mini whiteboards pair really well with turn and talks, allowing students to try a problem or gather their thinking before sharing with a partner.

• Finally, whiteboards are great for anything step by step. I can have students copy a problem down, do one step, then check it. Then the next step, and check that. This makes it easier to break a complex problem down into pieces, and figure out which pieces are hardest for students.

Mini whiteboards aren’t perfect. They can be a bit slow, allowing time for everyone to finish each problem. There’s a risk of copying, since students are working on one problem at a time and usually writing bigger than on paper. It takes some effort to create the routines. The whiteboards can be targets for destruction or graffiti. But all of those issues can be managed, and I think they’re absolutely worth the effort.

Stop and Jot

Asking a single question can be a good check for understanding, but in other cases I can get much better information by asking multiple questions. I always keep a big stack of half-sheets with five blanks on them in my classroom. Here’s the template if you’d like to use it.

I have this template for the questions.

I put the questions on the screen at the front of the room, and students write their answers on their half-sheet handouts. Here are a bunch of advantages of this check for understanding:

• I often use a stop and jot right before independent practice. An exit ticket is nice, but more useful is a middle-of-class ticket. I have students answer five questions, and then look at their work as they start practice. I can use this to identify students that need support, or realize that a large part of the class is confused about something, pause, and bring everyone together for a quick clarification.

• Asking multiple questions helps me identify where understanding breaks down. In the sequence of problems above, I can tell quickly whether a student needs help with the basics of percentages, or only the idea of percent increase/decrease.

• Sometimes with a stop and jot I’ll walk around the room to look at student work and focus on a specific question. I can’t take in five answers at once, but I can focus on question 4, and glance at 1, 2, and 3 if the student got 4 wrong. Other times I’ll collect the stop and jots and sort through them, then follow up with students individually while they work on an independent assignment.

• One problem here is that it takes time for me to collect and sort through the papers, which means students might be starting independent practice feeling confused. A nice strategy is to give students some quick fact fluency practice after the stop and jot, then move on to independent practice with the skill we’re working on. That gives me time to look at their work and plan for how to follow up before students dive in.

• Something I love about stop and jots is that they give me concrete questions to reference when I follow up with students. If a student is totally confused, I can work with them starting on question #1. If a student made one small mistake, I can show them and have them rework that problem.

A stop and jot isn’t too different from lots of other things I do in math class where I give students some math problems to solve on paper. The differences are that it’s easy to create on the fly, easy to collect and analyze, and marks a specific place where I’m checking student understanding and adjusting my teaching based on their answers. I could do something similar with most of the random handouts I give to students each class. But I find it helpful to have a specific place in my lesson where I check for understanding. I’m not trying to guide students to understand a new idea, I’m not trying to start a discussion, I’m not trying to launch independent practice; my only goal is to check for understanding and figure out what to do next.

A Few Thoughts

These tools have a lot of overlap. In some situations I could use one or the other. In general, I find mini whiteboards more helpful if I might want to provide some extra practice right away based on student answers, or if I want to check a few different topics at once. I find stop and jots more helpful if I want to do more careful analysis of student work, if the questions are longer, or if it’s helpful to ask several connected questions in a row and analyze them together.

When I first started using these tools they felt clumsy and stilted. It took practice to get good at them and figure out when and how to check for understanding. When I first started using stop and jot, I would plan the questions, the exact spot in the lesson to use them, and how I wanted to follow up. But as I got better at using these tools I saw more and more places to use them. Now, as I’ve gotten more comfortable, I often use them on the fly, coming up with a few questions when I see a need to check student understanding. I also mix these in if we’ve gotten through the lesson faster than I expected — if we have a bit more time than I thought, why not throw in an extra check for understanding? At the very least it provides a few extra questions of practice.

A lot of teachers have moved to technology to check for understanding. Having students open up their Chromebooks and using some digital tool that shows me their answers right away is certainly tempting. I’ve done plenty of that in my teaching. But I’ve moved away from it. Technology is just so fickle. This student’s Chromebook is dead and they forgot their charger. That student is checking their email. The other student has made their background some weird animated thing and is showing it to the students behind them. I’m not categorically against Chromebooks in class, we use them a bit. But I don’t think they’re the right tool to check for understanding. I want a check for understanding to be fast, easy to improvise, and give me data on every student. Trying to do all that with technology often falls short.

There are other strategies I can use to check for understanding. I can ask individual students questions. I can have students turn and talk about a question and listen in. I can use choral response. Those are all useful data points. What makes mini whiteboards and stop and jots stand out for me is how I can get data on literally every student in the classroom. That’s invaluable. It’s so easy to fool myself as a teacher, to think that students understand more than they do. Looking at every single student’s answer — or, in some cases, lack of an answer —forces me to be honest about where we are, and helps me make better decisions about where to go next.

For centuries we’ve used the declaration of ‘monster’ to eject individuals and groups from being respected as fully human

- by Surekha Davies

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In one of my recent blog posts, I talked at length about the virtues and advantages of building personal information intake system around RSS feeds. You get privacy and ownership over the distribution of information without any black box algorithms deciding what to show you (which inevitably ends up focusing on ads or engagement bait at some point). However, no system is perfect, and building your beautiful garden of RSS feeds is no different.

One of the major downsides of your little private feed garden is that it is isolated and static; therefore it requires active effort to discover new sources. Algorithmic feeds largely avoid this problem, which is something that everyone who shuns them should consider for their own benefit. In this article, I will share several ways how to keep your feeds fresh and interesting over time.

Disclaimer: I am a big fan of the so-called small web (or indie web), and much of my discovery is aimed at finding cool new small-web sites and blogs. However, the approaches listed below are mostly applicable to finding new sources of reading pleasure of any size and kind.

Ranked feeds and algorithms

Despite my apprehension towards algorithmic feeds, I actually do think they can be useful for growing your collection of RSS feeds. There are many websites and services that offer curated lists and recommendations based on your interests, tags or user signals like upvotes. The advantage is that you can target specific areas of interests.

Picking up 3D printing? Gardening? Birding? There are probably numerous blogs and sites you can relatively easily discover by looking up relevant categories, tags or search terms on RSS and news aggregators like Feedly, Inoreader, Flipboard or even Google News. These platforms will help you identify relevant feeds for individual categories or areas of interest - just visit a few links, get a feel for whether they’re for you, and if so, add it to your RSS aggregator of choice.

Another option is to utilize community platforms where users submit and upvote links. Prime examples of such sites are Reddit, which is of course full of subreddits for any and every hobby and area of interest, or if you want to get a little more IT-specific, Hacker News, Lobste.rs or Scour. On Reddit in particular, a lot of the posts may be simply questions or discussions with no links, and filtering for link-only posts isn’t universally available, so for the purposes of discovering new sites to subscribe to, you may have to dig a little. Hacker News and Lobsters, on the other hand, focus on links, but won’t be the best places to learn about woodworking or hiking or mountain biking.

Blog platforms also typically have some sort of a discovery mechanism, e.g., a “trending” or a “discovery” feed. You can find those on Bear blog, Wordpress, Ghost and many more. I particularly like the Bear blog’s trending page, as Bear itself is a great experience for both writers and readers, and you can actually subscribe to the trending RSS feed, which removes a lot of the friction from continuous discovery.

Curated lists and newsletters

For hand-picked recommendations, you can turn to various curated lists. First, there are lists of “notable” blogs, such as ooh.directory, Feedspot or Blogorama. They typically let you browse by categories or tags to narrow the recommendations down to your interests. However, it’s not always clear what the selection criteria for inclusion are, and if you are looking for blogs on specific topics, you might be better off simply searching the internet for something like “best <insert your interest> blogs”.

Second, I have seen abstractions over the blog ecosystem, such as weblogs.ai, which combines curation of blogs with some AI-based classifications, summaries and scoring. If you prefer to avoid AI-driven tools or want to try something akin to a blog-speed-dating experience, you can fire up Cloud Hiker. powRSS is also worth mentioning specifically because it focuses on curation of blogs posts from the “open, independent web”.

Last but definitely not least, newsletters. Most newsletters have an archive page with an RSS feed, meaning you could subscribe to them directly from your RSS feed, without going through your email client (my preferred way). But even without an RSS feed, a newsletter in your mailbox is a very potent source of new feeds. There are numerous newsletters that serve you curated lists of links, for example TLDR, Hacker Newsletter or Sentiers. For a list of tech/business newsletters, check out the Awesome newsletters list. For everything else, you could check out Letterlist or Ghost.

Searching using LLMs

If you do not shy away from LLMs, using them to find relevant blogs and sites (especially if you’re just starting) is a viable choice. Modern LLMs that can use web search are very good at coming up with search keywords and will typically cycle through several searches and collate the results for you. One of the real advantages of this approach is that you don’t have to know the lingo of the industry or the area of interest.

For example, when I asked an LLM to find guitar modification blogs (but intentionally used simplistic phrases like “making guitars sound better” or “changing parts”), it automatically refined my prompt with the niche-appropriate terms (“guitar mods”) and performed multiple targeted searches. The resulting list was definitely a good starting point.

Of course, this approach won’t cut very deep through the internet to pick up true “small web” gems, and some of the recommendations may be for defunct blogs or SEO spam. But if you’re not sure where to start in the category-based curated lists or subreddits, it may nudge you in the right direction.

Blog rolls

I have saved my favourite way of discovery as the last one: blog rolls. I won’t blame you if you haven’t heard of it, since it never really made it into everyday language and its popularity has definitely seen better days. A blog roll is simply a list of other sites or blogs that the author recommends (and likely subscribes to themselves).

Personally, I consider blog rolls quintessential to the small web and blogosphere, and I believe it is one of the best ways of discovering new blogs. A lot of the times, blogs can’t really be easily categorized beyond the vague “personal blog” label, which makes it complicated to find them in category-based lists or algorithms. Perhaps more importantly, there is something authentic and almost personal about finding a new interesting blog through an author you already follow. It’s almost like a recommendation from a friend.

If you have a blog of your own that does not sport a blog roll, go and create one! If you’re already deep in using RSS feeds, it will be minimal effort, and your readers will appreciate it. And if you are a reader, check the blogs you like for their own blog rolls. Mine is here.

How to grow your feeds in a healthy way

I already shared some tips on growing and maintaining your feeds, but here are a few more that are relevant to discovery:

• If you subscribe to multiple newsletters, sites and blogs that tend to cover current events or share trending links, you will face some amount of duplication. Some articles may get viral on social media, and links from sites like Hacker News often get reposted elsewhere. I believe some level of duplication may be inevitable, but you should prune your feeds if it starts bothering you.
• Don’t go on a huge subscribing spree if you get excited about finding new stuff to read. I recommend spacing it out, as subscribing to too many new feeds at once can be disorienting and can sour your reading sessions if you make a few bad judgement calls.
• It can be easy to misjudge how much you’ll like a blog or a site based on one article that you liked. The more trigger-happy you are to subscribe to new sources, the more trigger-happy you should be unsubscribing from the feeds that you no longer find interesting. It can take some time and reflection to realize you’ve been just scrolling past / marking as read specific feeds, and that it’s time to say goodbye.
• Don’t make reading your RSS a chore and don’t beat yourself up if you can’t quite catch up. Seeing a high number of unread posts after you got sick or got back from vacation can be daunting, but you don’t owe anyone anything. Your attention is your time, and we all have a limited supply of both, so we should use it judiciously.

Thank you for making it all the way through the article! I hope this helps you find amazing new stuff to read, and if you have not discovered the joy of the small web, I hope you will give it a chance. Happy reading!

“Opening locks” might not sound like scintillating social media content, but Trevor McNally has turned lock-busting into online gold. A former US Marine Staff Sergeant, McNally today has more than 7 million followers and has amassed more than 2 billion views just by showing how easy it is to open many common locks by slapping, picking, or shimming them.

This does not always endear him to the companies that make the locks.

On March 3, 2025, a Florida lock company called Proven Industries released a social media promo video just begging for the McNally treatment. The video was called, somewhat improbably, “YOU GUYS KEEP SAYING YOU CAN EASILY BREAK OFF OUR LATCH PIN LOCK.” In it, an enthusiastic man in a ball cap says he will “prove a lot of you haters wrong.” He then goes hard at Proven’s $130 model 651 trailer hitch lock with a sledgehammer, bolt cutters, and a crowbar.

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When I was in high school, my teacher once told us a crazy story. When he started teaching in Northern England in the late 1970s, he and the other teachers would often talk in the break room about how their students seemed to be getting dumber every year. It was so strange — the kind of thing you might say with a worried laugh but no explanation. Smart primary schoolers turned into middle schoolers that just didn’t get things.

Years later, he connected the dots: the school was at the bottom of a hill, in a little valley, and the playground right by the busy main road. All the exhaust fumes pooled and hung in the air there. And these were the 1970s: literally all the gasoline was leaded.1 This was lead poisoning. Over the years, the children were getting brain damage.

Nobody knew. There was no pediatric lead testing.2 Later pilot studies in Birmingham, Manchester, and Glasgow would eventually confirm this: children were found to have average blood lead levels of 3-5x the safe maximum. Just imagine what the severe cases looked like.

This story has stuck with me. It features the shocking and tragic loss of healthy lives — condemned to live in functional disability — brought about by many well-intentioned people doing their best, trusting that the status quo is safe and normal. But it often isn’t — what you hope and trust to be fine is secretly killing you.

The world has come a long way on this. Standards have improved substantially: houses are no longer being built with asbestos, lead paint is no longer permitted (though chances are your house has some), public water is mostly clean, and so forth. But better codes don’t go all the way: if the municipal water is fine but my house’s pipes are made of lead, that’s still a big problem. If mold is silently growing in my walls, nobody’s looking out for that — I’m on my own.

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And there are new dangers. Globalization means a world where nobody knows what’s in anything anymore because the supply chains are so complex, the financial incentives are to bring the costs down as much as possible, and when something is full of poison, you have no recourse. Somehow we wound up with steaks from Whole Foods being chock-full of BPAs — yes, even meat has microplastics!3 And regardless of whether you shop on Amazon or at Restoration Hardware, pretty much everything4 is sourced & manufactured far outside your control.

Is the furniture I sit in every day made with harmful substances? I don’t know. Are my plates, pots, and pans safe to eat from? No clue.5 And if they aren’t, there’s no way for me to assert my rights or collect a single penny from some faceless factory in Cambodia. If you think there’s any kind of quality control, there’s zero — nothing is getting inspected. Every nine months it turns out my protein powder contains heavy metals. The border can’t even stop counterfeit Rolexes from getting through, and the bar for listing a product on Amazon is the floor.6 I am sorry to say that for consumers, the buck stops with no-one but you. And your position is totally helpless.

Two years ago, I kept seeing these ads on the NYC subway. It’s so crazy: in one of the wealthiest cities on the planet, babies eating from lead-contaminated glassware is so pervasive a problem that a private company has to step up to do basic quality control.

NYC babies are not the only ones silently getting their IQs nuked because of careless manufacturers. Afghan children probably have the catastrophically highest levels of blood lead — even in the diaspora abroad — because virtually all the manufacturers of traditional Afghan cookpots were using lead-contaminated metals. Even when this was found out, it took Amazon over a year to take down the listings for the damn things. The level of public harm is off-the-charts. Chances are you don’t own one of these, but when’s the last time you might have eaten in a restaurant that does?

The problem is so overwhelming that you almost can’t engage it. There’s just too much stuff to check on your own. This is catnip for neurotic Type-As. You’ll drive yourself crazy if you try to fix it. And, in fairness, none of these hazards are big and likely enough on their own to warrant your deep-dive attention. It’s in aggregate that they’re impactful: in your life, most risk factors aren’t an issue at all, but there’s probably something that needs to be found out and fixed. The only solution is to delegate it to a third party that you can trust to do a really thorough job. Only a business with this as its core competency is capable of the breadth and depth required for this Herculean task.

In Germany, there’s a popular nonprofit which tests consumer goods for safety and publishes the results. When I was a baby, my mom followed their publications, and only bought the baby foods, diapers, etc. that had been deemed high-quality. Those ratings alone directed many thousands of dollars of high-margin spend for her. Consumer goods are as big as markets get, parents are willing to spend virtually any amount of money for the benefit of their children, and the product scope is endless. There’s going to be a generational company that uncompromisingly creates trust and will charge a hefty premium for never breaking that trust. Providing infallible peace of mind is the strongest of moats.

I am seeing the latent demand. Technology is empowering citizen scientists: consumers are taking charge of their health. They’re buying Whoop,7 Mira, Levels, Eight Sleep, Nucleus, Ezra, Function, etc. to understand their bodies, optimize their health, and catch potential issues way ahead of time. They’re starting to want things like Blueprint, where the manufacturer is staking their credibility on the work they’ve done to own the whole supply chain.

Soon the penny will drop with the public: health is not just about your body, but about your environment. People are starting to pay attention to air quality.8 They’re realizing that the “premium” consumer brands are full of microplastics. They’re waking up to the fact that life can and should feel better. Everyone wakes up congested, everyone gets headaches, everyone gets a rash sometimes — but these “normal” experiences are your body telling you that something is wrong. It’s just so common that it’s normalized. And so many health outcomes that people talk about in terms of luck are actually deterministic, but people gloss over there being causality at work.9 The problem is large. And we have the science to do better.

Health is the final frontier. The idea of luxury was once conferred by design, materials, and manufacturing — but today, even the highest-end goods are now instantly replicated for pennies on the dollar. The question that remains is what lurks inside: the peace-of-mind escape from hidden hazards is not just necessary, but offers infinite optimization.

This will be a big business. It has been on my mind for many years now. I’ve seen all the startups that have taken a stab here — Yuka, Oasis, Tap Score, you name it. But while I admire their missions, I don’t think anyone’s historically gotten this right as a business. Now I’ve finally met the right founders taking the right approach: empowering people as citizen scientists, and taking on the big task of monitoring for and remediating hazards at home. This is very important to me, and I am excited to help them succeed. If this mission sounds interesting to you, email me at contact@johnloeber.com and I’ll put you in touch.