How to Keep a Startup Journal: The Venture Log and Book Log

By Kasper-Tanakrit Sermsuksan · Global Venture I: Playbook · Block A

You are here: A-10 · Block A · Orientation & Mindset · article 10 of 10 · Form A+B · Next: B-01 The Global Entrepreneurial Mindset

In short: A venture log is a startup journal. After every stage of work, each person writes a four-line update — the tool you applied, what changed in your idea, a link to the evidence, and your readiness self-score. A book log is your own two-line note per chapter of a book that matters to your venture: one takeaway and one way it applies. Together they turn weeks of work into a visible story of how your idea — and you — changed. They take minutes to write, and they save you days at the end.

Try it in 10 minutes: Pick one IRL area — Customer is the easiest. In two lines, write what level 9 would look like for your idea. Then write today's honest score for that area and the one piece of evidence behind it. That is the first line of your first Venture update.

Picture the last week of a project.

Your team sits down to write up everything you learned. Someone asks what the second customer said. Nobody remembers.

Someone else thinks the idea changed in week three. Or was it week four? The evidence is somewhere in a group chat, three hundred messages up.

I want to save you from that week.

The fix is simple, and it works: write it down while it is fresh.

What you do not write down, you cannot see. What you cannot see, you cannot improve. (How I used my own notes to find the hours I was losing each day is in FISHE Capital™ × CSTO™ (Personal Edition).)

Why keep logs at all?

Because the learning happens after the doing — in the reflection.

Most people skip it. They run an interview, feel good or bad about it, and move on. A week later, the lesson is gone.

I teach in a simple loop: Read → Do → Reflect → Debrief. The logs are the Reflect step, written down. Educators call this experiential learning: you have an experience, reflect on it, make sense of it, and try again¹.

The habit is borrowed from the best founder programs too. In Steve Blank's Lean LaunchPad classes, teams report their lessons learned every week² — what they believed, what they found out, what they will do next. The Venture Log is our version.

There is a practical reason as well. If you have to write up what you learned at the end, eight rounds of honest updates mean the report almost writes itself.

Who writes the Venture Log, and what goes into an update?

I recommend one Venture Log per team, and one Venture update per member. After every stage of work, each of you writes your own update, in four lines:

1. Tool applied — which framework or method you used this time.
2. What changed in the idea — one or two sentences. "Nothing changed" is allowed, but say why.
3. Evidence link — interview notes, a photo, a sign-up sheet, a canvas. Something someone else can check.
4. Readiness self-score — your score in each area, and which one moved.

That is it. Short, honest and linked to proof.

Why one each, and not one for the team? Because two people rarely learn the same thing from the same week. Where your updates disagree is often where the learning is.

✦ If you are doing this as part of Global Venture I: Playbook

You write your Venture update at the end of every block form, then fill in the form's "AI used for:" field. Your update is individual work and counts in the 15% for block forms. Together, the team's updates make the Venture Log, and your final interview report draws on all 12 interviews and your Venture Log.

What does a good Venture update look like?

Weak entry

Tool: Interviews.
Changed: We learned a lot about customers. They liked our idea.
Evidence: —
IRL: CRL 4.

Strong entry [illustrative]

Tool: Interview Masterclass — 3 customer interviews (Thai Nourish).
Changed: We thought parents of diabetic children were our customer. All three said the grandparent who cooks decides what the family eats. We are now testing grandparents as the user and parents as the payer.
Evidence: link to interview notes (3 files) and our updated customer map.
IRL: CRL 2 → 3 (first direct feedback on the problem); BRL 1; TMRL 2; FRL 1.

The weak entry has no evidence, an opinion ("they liked our idea") instead of facts, and a score the evidence cannot support.

The strong entry names who said what, what changed, where the proof is, and why the score moved.

If I can check it, it counts. If I can't, it is a feeling.

What does level 9 look like for your idea?

The KTH user guide suggests describing what level 9 would look like for your idea before scoring³. Do it once, for each area, before your first score.

Level 9 is the fully grown version. Customers buying at scale. A business model that clearly works. A strong, complete team. Funding in place for growth.

Write, in plain words, what that would mean for your venture. For a Thai Signals screening tool, level 9 on the customer side might mean clinics across several countries using it every day [illustrative].

Why do this? Because a score of 3 means nothing until you know what 9 looks like.

Picturing the end makes you honest about the start. Without it, it is easy to score yourself too high in week one — and then watch the score "drop" when you learn more.

A drop is not failure. It is calibration.

Write your level-9 picture once, in your first update. Come back to it at the end.

The levels themselves come from the KTH Innovation Readiness Level: six areas — Customer (CRL), Technology (TRL), Business model (BRL), IP (IPRL), Team (TMRL) and Funding (FRL) — each scored 1 to 9 against KTH's official criteria. A level counts only when all its criteria are met. Full guide: The KTH Innovation Readiness Level: How We Use It (and What We Expect).

✦ If you are doing this as part of Global Venture I: Playbook

Write your level-9 picture in your first Venture update and come back to it in Block H. By the end of Global Venture I, aim for CRL 3–4 · BRL 3 · TMRL 3–4 · FRL 2–3; TRL and IPRL are recorded only.

What is the Book Log, and when is it due?

A book log is the same habit, applied to reading.

Pick one book that matters to what you are building. Read it in order. The Book Log is yours alone. For each chapter, write two lines:

1. One takeaway — in your own words.
2. One way it applies to your venture — this week, not someday.

The second line is the one that matters. A takeaway you never use is just a nice quote.

✦ If you are doing this as part of Global Venture I: Playbook

The book is mine, The Startup Mindset, read in book order: 7 Misconceptions, 29 short chapters, and "Three Reasons to Just Start Already". Either the Thai original or my own English translation is fine.

• 8-week — Read: 7 Misconceptions + Chapters 1–8 — Log it in: Form A+B (Week 1)
• Chapters 9–19: Form C (Week 2)
• Chapters 20–29 + Three Reasons: Form D (Week 3)
• 16-week — Read: All chapters, in book order — Log it in: Finished by Week 6

The stories come back later. When we reach growth models in Block F, I will ask you to look at what you wrote about Chapter 26.

What does a good Book Log entry look like?

Weak entry

Chapter 2: Very inspiring. Never give up.

Strong entry [illustrative]

Chapter 2 — The Sushi Restaurant That Almost Never Opened.
Takeaway: When every head chef said no, Atom did not lower the standard. He changed who he asked — the assistant chefs — and kept the goal.
Applies to us: The hospital directors we wrote to for Thai Care have not replied. Instead of dropping the idea, this week we will ask physiotherapists and nurses for our first interviews.

Notice what the strong entry does. It turns a story about sushi into a decision about this week's interviews.

How do you keep a startup journal without it becoming a chore?

• Write within a day. After an interview or a workshop, while it is fresh.
• Link, don't retype. Put the notes in a shared team folder and link them.
• Read each other's updates. One log per team, one update per member — compare them before you meet. Where you disagree is often where the learning is.
• Be honest about what did not change. "We tried, it didn't work, here is why" is a strong entry.
• Use your own words. AI can help you research and draft, but your update is a reflection and must be yours.

I recommend keeping it boring. Same four lines, same place, every time. The habit matters more than the format.

✦ If you are doing this as part of Global Venture I: Playbook

Say what you used AI for in the form's "AI used for:" field. The full rule is in About the Course.

Frequently asked questions

What should I write in a startup journal?
Four things, every time: what you tried, what changed in the idea, the evidence (with a link), and where your venture stands now. In Global Venture I that is the four-line Venture update.

How often should I update my venture log?
After every stage of work — in Global Venture I, once per block form. Write the notes behind it within a day of each interview or workshop.

Is the Venture Log a team or individual task?
Both. I recommend one Venture Log per team, with each member writing their own update. (In Global Venture I, each update is graded individually.)

Is the readiness self-score graded?
No. You are graded on evidence and work quality. An honest lower score is never penalized.

What if my score goes down?
That is normal. It usually means you learned something and scored more honestly.

✦ A Note for Global Venture I Students · Block A: Orientation & Mindset · Form A+B

Your first Venture update is your baseline. It does not need to be impressive. It needs to be true.

The rules in one place: one Venture Log per team, one Venture update per member, written at the end of every block form in four lines (tool applied · what changed · evidence link · readiness self-score), plus the "AI used for:" field. Your update is individual work and counts in the 15% for block forms. The Book Log is yours alone, on the schedule above.

Do this before class:

1. Write your level-9 picture for your idea, one line per area.
2. Write your first Venture update in Form A+B: your challenge route, your riskiest assumption, and your baseline readiness self-score.
3. Start your Book Log: 7 Misconceptions through Chapter 8 (8-week). In the 16-week format, start now in book order and finish by Week 6.

Pre-class check (in Form A+B):

1. What are the four lines of a Venture update, and who writes it?
2. Why describe level 9 before you score yourself?
3. What two things do you write for each chapter in the Book Log?

Your progress: All areas — the Venture Log is where every readiness self-score and its evidence live, from baseline in Block A to the final score in Block H. How we measure progress

Skills you practice: Motivation and self-awareness · curiosity and lifelong learning · learning through experience · planning and management.

Based on the KTH Innovation Readiness Level™ by KTH Innovation, licensed CC BY-NC-SA 4.0 (kthinnovationreadinesslevel.com).

Keep reading

• The KTH Innovation Readiness Level: How We Use It (and What We Expect) — how to score each area
• The Global Entrepreneurial Mindset — Block B starts here
• Can Entrepreneurship Be Taught? — "the reflection loop is the learning"
• Letters to Future Self — where the logs end up

All articles in Block A · Orientation & Mindset

• A-01 The Story Behind SEA Bridge
• A-02 Can Entrepreneurship Be Taught?
• A-03 SEA Bridge: The Cross-Border Venture Studio
• A-04 Should You Start a Company?
• A-05 About Global Venture I: Playbook
• A-06 The Entrepreneur Interview
• A-07 Thank-You Letters
• A-08 The ASEAN Friend Interview
• A-09 How to Choose a Startup Idea
• A-10 How to Keep a Startup Journal (you are here)

References

1. Kolb, D. A. (1984). Experiential learning: Experience as the source of learning and development. Prentice Hall. (Title page: https://www.fullerton.edu/cice/_resources/pdfs/sl_documents/Experiential%20Learning%20-%20Experience%20As%20The%20Source%20Of%20Learning%20and%20Development.pdf; cycle summary: Hong Kong Baptist University, https://chtl-bu.hkbu.edu.hk/documents/experiential-learning.pdf) — accessed Nov 2026.
2. Blank, S. (2011, March 8). A new way to teach entrepreneurship – The Lean LaunchPad at Stanford: Class 1. https://steveblank.com/2011/03/08/a-new-way-to-teach-entrepreneurship-the-lean-launchpad-at-stanford-class-1/ — accessed Nov 2026.
3. KTH Innovation. (n.d.). KTH Innovation Readiness Level™ model – User guide. Copy hosted by Fonds de recherche du Québec: https://frq.gouv.qc.ca/app/uploads/2025/02/kth-irl-user-guide_va.pdf — accessed Nov 2026.
4. Sermsuksan, K.-T. (2023). The Startup Mindset [in Thai], Chapter 2. Wish Publishing (สำนักพิมพ์วิช). English: the author's own translation, not yet published.

Further reading

• Blank, S., & Dorf, B. (2012). The startup owner's manual: The step-by-step guide for building a great company. K&S Ranch.

About the author: Kasper-Tanakrit Sermsuksan is the Founder of SEA Bridge and a Visiting Lecturer in Computer Engineering and Digital Technology at Chulalongkorn University's Faculty of Engineering. Learn more →