# Adult (a6a)

[Browse datasets](<../../>) 

`libsvm:a6a@1` · Registry `1.4.0`. Default version in this registry. 

The a6a binary classification variant of the UCI Adult census income dataset, distributed by LIBSVM with predefined training and test artifacts. The task predicts whether annual income exceeds $50,000 using 123 binary features derived from the original 14 attributes. 

<a id="dimensions-and-tasks"></a>

## Dimensions and tasks

| Task | Type | Split | Samples | Predictors |
| --- | --- | --- | --- | --- |
| default | classification | test | 21,341 | 123 |
| default | classification | train | 11,220 | 123 |

Predictor counts follow each task's feature selection and exclude targets and identifiers. Sample counts are reported separately for each split. 

<a id="retrieve"></a>

## Retrieve

These examples pin both the dataset version and the registry's exact index. An uncached dataset requires network access to its source. The CLI retrieves verified artifacts. The language clients also decode them. 

<a id="python"></a>

### Python

```python
from datamonger import Registry, fetch_data

registry = Registry(
    release="1.4.0",
    index_sha256="ef83679266af9fcbb9ea194acdfb9bb6c380b440a574fc2ee7292899c5102909",
    index_url="https://github.com/jolars/datamonger/releases/download/registry-v1.4.0/index.json",
)
data = fetch_data("libsvm:a6a@1", registry=registry)
```

<a id="r"></a>

### R

```r
library(datamonger)

registry <- registry_selector(
  release = "1.4.0",
  index_sha256 = "ef83679266af9fcbb9ea194acdfb9bb6c380b440a574fc2ee7292899c5102909",
  index_url = "https://github.com/jolars/datamonger/releases/download/registry-v1.4.0/index.json"
)
data <- fetch_data("libsvm:a6a@1", registry = registry)
```

<a id="julia"></a>

### Julia

```julia
using Datamonger

registry = registry_selector(
    "1.4.0",
    "ef83679266af9fcbb9ea194acdfb9bb6c380b440a574fc2ee7292899c5102909",
    "https://github.com/jolars/datamonger/releases/download/registry-v1.4.0/index.json",
)
data = fetch_data("libsvm:a6a@1"; registry=registry)
```

<a id="cli"></a>

### CLI

```sh
cat > datamonger-registry.json <<'JSON'
{
  "index_sha256": "ef83679266af9fcbb9ea194acdfb9bb6c380b440a574fc2ee7292899c5102909",
  "index_url": "https://github.com/jolars/datamonger/releases/download/registry-v1.4.0/index.json",
  "release": "1.4.0",
  "schema_version": 1
}
JSON
datamonger --selector datamonger-registry.json fetch 'libsvm:a6a@1'
```

<a id="representation-and-variables"></a>

## Representation and variables

Tabular data with a sparse representation. Decoder: `libsvm-split` version 1. 

| Component | Kind | Type | Shape |
| --- | --- | --- | --- |
| train\_features | sparse\_matrix | float64 | 11,220 × 123 |
| train\_response | vector | int64 | 11,220 |
| test\_features | sparse\_matrix | float64 | 21,341 × 123 |
| test\_response | vector | int64 | 21,341 |

<a id="preprocessing"></a>

## Preprocessing

<a id="upstream"></a>

### Upstream

Status: documented. 

LIBSVM documents 123 features and the training and test sizes. The quantile boundaries, fitting population, handling of original missing values, and split selection procedure have not been established. 

**feature-encoding.** The six continuous Adult attributes are discretized into quantiles and represented by binary indicators. Each category of the eight categorical attributes is represented by a binary indicator. 

Evidence: [https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary.html\#a6a](<https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary.html#a6a>), [https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary.html\#a1a](<https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary.html#a1a>) 

<a id="datamonger"></a>

### Datamonger

Status: none. 

Datamonger decodes the provider artifacts without additional statistical preprocessing. 

Evidence: spec/decoders/libsvm-v1.md 

<a id="provenance-and-citation"></a>

## Provenance and citation

Provider: LIBSVM. Upstream name: a6a. Retrieved: 2026-10-26. 

[Original source](<https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary.html#a6a>) 

Authors: Barry Becker, Ronny Kohavi. 

Becker, B., and Kohavi, R. (1996). Adult \[Dataset\]. UCI Machine Learning Repository. [https://doi.org/10.24432/C5XW20](<https://doi.org/10.24432/C5XW20>). 

Original Adult dataset, as cited by UCI. 

John C. Platt. Fast training of support vector machines using sequential minimal optimization. In Advances in Kernel Methods - Support Vector Learning. MIT Press, 1998. 

Reference JP98a associated with these variants by LIBSVM: [https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/ref.html\#JP98a](<https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/ref.html#JP98a>). 

<a id="license"></a>

## License

Unknown 

UCI identifies Barry Becker and Ronny Kohavi as the Adult dataset creators and licenses the original dataset under CC BY 4.0: [https://archive.ics.uci.edu/dataset/2/adult](<https://archive.ics.uci.edu/dataset/2/adult>). The LIBSVM page identifies Adult as the source and documents its feature encoding but states no license terms for the transformed artifacts: [https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary.html\#a6a](<https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary.html#a6a>). The applicability of the original license to these distributed artifacts has not been established. 

<a id="artifacts"></a>

## Artifacts

Total download: 2.2 MiB. Sizes describe the distributed files, including any compression. 

| Artifact | Format | Compression | Size | Distribution | Preservation |
| --- | --- | --- | --- | --- | --- |
| train | libsvm | none | 784.0 KiB | upstream-only | unknown |
| test | libsvm | none | 1.5 MiB | upstream-only | unknown |

[train: upstream](<https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary/a6a>) 

[test: upstream](<https://www.csie.ntu.edu.tw/~cjlin/libsvmtools/datasets/binary/a6a.t>) 

<a id="versions-in-this-registry"></a>

## Versions in this registry

[1](<1>) (default) 

<a id="registry-record"></a>

## Registry record

Download the [complete registry record](<../../../assets/0f8c47fec6794b00b8ae8b9d32db9cf4491be2337b52714cd69667efd808c990.bin>), [registry selector](<../../../assets/34c66958a7fbdc23b69bacece50c1f1e9a097760400133967cecb6086963cdb1.bin>), or [full registry index](<https://github.com/jolars/datamonger/releases/download/registry-v1.4.0/index.json>). 

Index SHA-256: `ef83679266af9fcbb9ea194acdfb9bb6c380b440a574fc2ee7292899c5102909`.