Evidence, not stories
Archaeology studies the human past through what people left behind: buildings, tools, pottery, bones, seeds, burials, rubbish and the changes they made to the land. Unlike history written from texts, much of this evidence was never meant to communicate anything. A rubbish pit tells us what people threw away, not what they thought about it. Reconstruction therefore means careful inference, and good archaeologists are explicit about which parts are observed and which are interpreted.
The work usually moves through a few broad stages: finding sites, recording and excavating them, analysing the finds, dating them, and finally building an interpretation. Each stage has its own methods, and each introduces its own uncertainty.
Finding and surveying sites
Many sites are found long before anyone digs. Surveyors walk fields and record scatters of pottery or worked stone on the surface, a method often called fieldwalking. Maps, old aerial photographs and satellite images help identify mounds, walls and field boundaries. In some regions, laser mapping from aircraft has revealed settlements hidden beneath vegetation, and remote sensing now complements ground survey in many parts of the world.
Geophysical methods look beneath the ground without disturbing it. Magnetometers detect small changes in the magnetic field caused by ditches, kilns and hearths. Ground-penetrating radar and resistivity surveys can outline buried walls and floors. These techniques are not perfect, since results depend on soil and moisture, but they help archaeologists decide where to dig and where to leave the ground alone.
Excavation as controlled destruction
Digging a site destroys it, because a layer can only be excavated once. That is why modern excavation is built around documentation. Earlier work was often much less careful. Treasure was the goal, and a famous case is Schliemann at Troy, where a deep trench cut through levels that later specialists considered valuable. The Mohenjo-Daro excavation history shows a similar shift over the twentieth century, from clearing large areas to recording evidence layer by layer.
Today the basic unit is the context: a single deposit, cut, wall or fill. Excavators remove one context at a time, usually in the reverse order from which it was laid down, and record its position, soil, finds and relationships to its neighbours. In the 1970s Edward Harris devised a diagram, now called the Harris matrix, that shows how contexts relate in time. Mortimer Wheeler’s grid of trenches with standing walls of earth, called baulks, was an influential earlier approach, and many projects now adapt such ideas to local conditions. In the specialised setting of Mesopotamian archaeology, where mudbrick walls can be almost the same colour as the soil around them, fine distinctions of texture and moisture become essential.
Everything is recorded in several ways at once: written context sheets, scale drawings, photographs and, increasingly, three-dimensional digital models and survey instruments that fix each find’s position.
Recovering what is easy to miss
Large finds are only part of the picture. Excavators often pass soil through sieves, or wash it in water so that light material floats, to recover tiny seeds, charcoal, fish bones and beads. These small remains can show what people ate, which woods they burned and how they used rooms.
Specialists then study each category. Zooarchaeologists identify animal bones, archaeobotanists identify plant remains, and osteologists examine human skeletons for age, sex, injury and disease. Conservators stabilise fragile objects. Residue analysis can sometimes detect traces of foods or drinks absorbed into pottery. Analysis of well-preserved bodies, including the mummy scientific study that uses CT scanning, adds further information without opening a wrapping or a coffin.
Dating the evidence
Archaeologists distinguish relative dating from absolute dating. Relative dating says that one thing is earlier than another, based on stratigraphic order or on changing styles of objects. Absolute dating gives a calendar range, using methods such as radiocarbon dating or tree-ring dating. Neither approach is a stopwatch. Radiocarbon results come with a margin of error, and pottery styles are tied to places and communities, not to the year.
Good chronologies combine several lines of evidence. A layer may be ordered by stratigraphy, linked by pottery to other sites, and anchored by a few radiocarbon samples or by a written record that names a king or an event. Even a famous collection such as the Dead Sea Scrolls has been studied through handwriting style, language and radiocarbon measurement together, and the methods have broadly pointed in the same direction.
From finds to interpretation
Interpretation is where most debates begin. Archaeologists use analogy, comparing what they find with better-known societies, with historical records and with observations of living craft traditions. Experimental archaeology tests ideas by trying them out, for instance by firing replica pots or building a small house from mudbrick to see how it behaves.
Underwater archaeology methods follow the same principles in a harsher setting, with divers or remotely operated vehicles recording shipwrecks and drowned harbours before anything is lifted. Wherever the work takes place, the aim is to move from individual finds to questions about economy, belief, society and change, and to be clear about the reasoning at each step.
A worked example in outline
Imagine a team excavating a small mudbrick house. They record the floor, a hearth, a rubbish pit cut into the floor and the collapsed wall above, each as a separate context. Sieving the hearth fill yields charred barley and a few fish bones, and the pit contains broken jars. The jars match a pottery style known from other sites, and a charred seed from the hearth gives a radiocarbon range. Together these suggest when the house was used and what its occupants ate. They do not say how many people lived there, what language they spoke or whether the house was typical, and a careful report says so.
What evidence cannot show
The record is incomplete in predictable ways. Wood, textiles, leather and food rarely survive except in very dry, waterlogged or frozen conditions, so the surviving evidence favours stone, fired clay and metal. Wealthy people and monumental buildings are better represented than ordinary households. Only a small share of any site is usually excavated, so conclusions rest on a sample.
Some questions may never be answered from material alone. Scripts that remain undeciphered, such as the long-running Indus script debate or Linear A script from Bronze Age Crete, show how much can be lost when no readable text survives. Even with texts, writers give the view of the literate few. Names, beliefs, languages and identities are hard to read from objects, which is why a style of pottery should not simply be equated with a people.
Responsible archaeology therefore offers well-supported accounts rather than final answers. New methods and new excavations regularly revise old pictures, and modern projects increasingly work with descendant communities and local authorities, who have their own knowledge of the places and their own views on how remains should be treated.