Empirical Science

Empirical Science

In Factorio, science is a crafting recipe: put the packs in a lab and the technology arrives, the same on every map. This mod adds research of the other kind. You have a question, the answer is hidden in your map, and the only way to learn it is to run experiments and read the data.

Feed a machine an ordinary item beside its recipe, such as coal, stone or sulfur, and it may make more products, run slower or pollute less. It may also do nothing at all, or do harm. Which additive helps which recipe is drawn fresh for every map. No wiki has the answer, and what you learned in your last game does not carry over.

Doing science

• One sample proves little. Measurements are noisy. An analysis station reads each sample against a control and gives an estimate with a range, and the range narrows only as samples accumulate. You decide when the evidence is good enough to bet a factory on.
• Effects trade off. An additive that adds products can also slow the machine, raise its pollution or change its power use. Some help at a low dose and harm at a high one, so finding the best dose is an experiment of its own.
• Patterns carry, up to a point. The mod studies 35 recipes and 33 additives. Additives belong to families and recipes to processes, so a result on gears hints at steel. Testing every mixture at every dose, temperature and planet would take about 19 billion trials. The Theory tab fits the family laws to your evidence and says which trials are worth running.
• Open questions pay. Analysing samples makes empirical science packs, and a sample makes more when its question has few results. Repeating a settled result earns less than asking something new.
• The truth comes out at the end. When you finish, the report sets each of your findings against the true effect. A 95% bound still misses now and then, and if one of yours did, you earn an achievement for it: Replication crisis.

How it plays

• Trials. A test bench makes a batch of a recipe with a dose of an additive, taken from a hopper beside it. Most of the batch comes out, and one sample with it.
• Analysis. An analysis station reads samples, using science packs. A large lab needs several stations.
• Empirical science packs. Labs use them for the mod's technologies.
• Production. A hopper doses the machines it touches that make a recipe the mod studies. A fluid hopper doses the machines along its sides. A dose that works makes more products per craft. Solid additives leave a residue, which leaves the machine with its products.
• Findings. A finding is an effect you proved and then produced with. Meet each reached planet's quota and enough major findings to finish. You can keep playing after.

The Empirical Science screen

• Screening: every additive tried on a recipe, at its best dose: its effect on yield, speed, pollution and power, its net gain after its own cost, and the empirical science packs its next sample makes.

• Dose-response: one additive's results dose by dose, a fitted curve and the best dose with its range. Automatic picks the model, or pick one.

• Mixtures: additives dosed together, on a heat map.

• Coverage: which recipes and families you have tested, and where the gaps are.

• Theory: fits the family laws to all your evidence and suggests what to test next.
• Findings: each planet's quota and the major findings, with what is left to prove or produce, and when each was completed.

• Presets: save a dose you trust, then pick it from any machine's dose panel.
• Progress: samples, empirical science packs, settled questions, findings and products made with a dose, over game time.
• Notebook: one page of notes, shared by the force and saved with the map.

Research

• Analysis precision narrows every range. Analysis productivity analyses more samples per science pack.
• Additive mixing: several additives in one machine.
• Fluid heating: heaters that bring a fluid additive to its best temperature.
• Lab circuits 1 to 3: the circuit features below, in turn.
• Premixes of two additives, and catalysts activated from residues, are unlocked by evidence, not by research.

By era and planet

• Early: coal, stone, stone brick and copper cable.
• Oil era: sulfur, plastic, solid fuel, oils, acids, premixes and catalysts.
• Fluid heating: fluids and liquid premixes work best at a temperature of their own. Evidence is kept per temperature band. A curve still rising in the hottest band means the best temperature is higher.

With Space Age

• Vulcanus: the pressure heater reaches the hot optima on any planet, burning pressure charges made from tungsten carbide.